Panama Canal

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Panama Canal
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Baxter, William
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Ackerman, Holly ( donor )
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University of Florida
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Ja





Nombre de ious
I.C.C. S Pit'


ISTHMUS
WITH
COMPLETED CANAL

SCALE
Miles
0 5 10 15
Kilometres
0 5 10 15 20












THE PANAMA CANAL



A BRIEF ANDSIMPLE DESCRIPTION

OF THE

ESSENTIAL FEATURES




BY
WILLIAM M. BAXTER, JR.
The Official Guide of the Isthmian Canal Commission


ENLARGED AND ILLUSTRATED
1913







































COPYRIGHT, 1918, BY
WM. M. BAXTER, JR.














LIST OF ILLUSTRATIONS.


Page
Culebra Cut, looking north from the Con-
tinental Divide . . 8
Flat Arch in the Church of San Domingo,
Panama . . 14
Old French Locomotives, near Empire,
Canal Zone . . 16
Abandoned French Ladder Dredges 18
Old French Excavation in Cut, near Empire 22
Steam Shovel Loading Rock for the Toro
Point Breakwater . 28
Steam Shovel in Culebra Cut, buried under
small rock slide, May 31, 1912 32
Slide of 300,000 cubic yards in the East
Bank of Culebra Cut, August 21, 1912 34
Gatun Locks in Course of Construction 36
Cross-section of Lock Chamber and Walls,
Gatun Locks . . 40
Entrance to Upper Gatun Lock from the
Lake . . 42
General View of the Pedro Miguel Lock 44
Sanitary Drip Barrel . . 48














FOREWORD.

The idea of the construction of a canal across
the Isthmus has been the dream of all nations of
the world ever since the day when Balboa first
landed on the Isthmus in 1500. He had hardly
set foot on dry land before he began the search
for a natural waterway between the two continents.
Failing to find anything of the kind, he had one
of his followers, an engineer named Saavedra,
prepare plans and surveys of an artificial water-
way, but, after studying the subject for a period
of more than ten years, he reported on the pro-
ject as being impracticable.
For over two centuries following this the project
dropped from sight and it was not until the early
part of the nineteenth century that the matter
was again taken up. In 1814 Spain again under-
took the consideration of a canal, but without any
result. Following this both England and France
became interested and made many studies and
surveys of various routes.
In 1835 the United States joined the list of those
interested in the construction of a canal and had
studies made of several of the feasible routes.
It is interesting in this connection to know that,
even before this time, Goethe had prophesied
that the United States would eventually have to
build the canal.








In 1838 France secured a concession to build
a canal, but allowed it to lapse through failure to
do any work.
In 1848 Messrs. Aspinwall, Chauncey and
Stephens secured a concession from the Govern-
ment of New Granada for the construction of a
railroad across the Isthmus, which work they
carried to a successful conclusion in 1855. For
a while this road filled the demand for a trans-
continental highway, but in 1870 the United States
again became interested and entered into an
agreement with Colombia for the construction
of a canal; nothing was done, however, and in
1876 a Frenchman, Lieutenant L. N. B. Wyse,
secured a concession to build a canal and it was
his concession that was later transferred to the
Universal Interoceanic Canal Company. This
company began active construction work in 1881,
but failed in 1888 and, although a new company
was organized in 1894 it continued operations on
a small scale, doing simply enough to maintain
its franchise, until 1904, when it sold out to the
United States.
On April 23, 1904, the stockholders of the New
Panama Canal Company formally authorized
the sale of the company's property to the United
States upon payment to the company of the sum
of $40,000,000. The transfer of the property on
the Isthmus was made May 4, 1904, the United
States being represented by Lieutenant Mark
Brooke, Corps of Engineers, U. S. Army.















THE PANAMA CANAL.













































CULEBRA CUT, LOOKING NORTH FROM THE CONTINENTAL DIVIDE.













THE PANAMA CANAL.

THE CANAL ZONE.
HE Canal Zone is a strip of land ten miles
wide, five miles each side of the center
line of the Canal, extending from the At-
lantic to the Pacific. All told, it contains 436
square miles, of which the United States now
owns about 363 square miles. The remainder is
privately owned and was not acquired by the
Government, as it was not needed for the con-
struction of the Canal. If, however, this land
should ever be needed, the United States can by
its treaty right acquire, either by purchase or by
the exercise of the right of eminent domain, any
lands, buildings, water rights, or other properties
necessary for the construction, maintenance,
operation, sanitation, or protection of the Canal.
The two cities of Panama and Colon, although
within the boundaries of the Canal Zone, are ex-
cluded from it and are under the Government of
Panama. They have no outlet, however, except
through the Zone. The United States reserves
the right to enforce sanitary ordinances in those
two cities, and also to maintain public order in the
event that the Republic of Panama is unable to
do so.









ROUTE OF CANAL.


The Canal traverses this Zone from Colon to
Panama in a general southeasterly direction,
Panama being located 22 miles east of a line
running due south from Colon.
In passing through the Canal from the Atlantic
vessels enter a sea-level channel extending from
deep water in the Atlantic to the foot of the locks
at Gatun. This channel is 7 miles in length, 500
feet wide and 41 feet deep.
At Gatun, vessels are lifted from sea-level to
85 feet above through a flight of three locks,
passing directly into the waters of Gatun Lake.
Gatun Lake is an artificial body of water with
an area of approximately 164 square miles. This
lake is formed by impounding the waters of the
River Chagres and its tributaries by means of a
large dam at Gatun, where there is a break in the
range of hills which surround the basin of the
Chagres. By building a dam a mile and a half
long across this gap, it is possible to back up the
waters of the Chagres and form the Gatun Lake.
The surface of this lake stands 85 feet above sea-
level, the summit level of the Canal, and extends
from Gatun clear through the Culebra Cut to
the southern end at Pedro Miguel, a distance of
32 miles. From the foregoing, it can be clearly
seen that the Culebra Cut is merely a spur of
the Gatun Lake, the same water level existing
in the Cut as in the balance of the lake.
[10]








Vessels after entering the lake may go at
practically full speed for a distance of 23 miles
from Gatun to the mouth of the Cut. The first
16 miles of the channel through the lake is to be
1,000 feet wide and is marked by buoys on the
surface of the lake, then for four miles the chan-
nel is to be 800 feet wide, narrowing to 500
feet for three miles before entering the Cut.
Through the Culebra Cut, which is 9 miles in
length, the channel is to be 300 feet in width at
the bottom. Passing through this Cut at a re-
duced speed vessels arrive at the Pedro Miguel
Lock at the south end, through which they are
lowered in one step from 85 feet above sea-level
to 55 feet above, a drop of 30 feet, passing out into
Miraflores Lake, a small artificial lake covering
an area of about two square miles. This lake
is formed by impounding the waters of the Cocoli,
the Rio Grande and the Pedro Miguel Rivers by
means of the dam, locks and spillway at Mira-
flores. The dam at this point runs practically
parallel to the locks on their west side instead of
at right angles to them. This is done in order
to take in the Cocoli River, which comes in from
the west, striking midway of the locks, which
makes it necessary either to divert this stream or
else to build a dam so as to throw it back into the
lake. The latter plan gives additional water
for the lake and avoids the silting up of the sea-
level portion of the Canal at the point at which the
diverted Cocoli would enter it. The spillway is
[11]








located on the east side of the locks between the
side wall and a rocky point, and is of sufficient
size to discharge all the water that might flow
through one of the twin locks at Pedro Miguel
in the event that an accident should establish
free communication between Gatun and Mira-
flores Lakes. In this way, an accident at Pedro
Miguel does not necessarily endanger the locks
at Miraflores.
Passing through the Miraflores Lake a dis-
tance of a mile and a half through a channel 500
feet in width the vessels arrive at the Miraflores
Locks and pass down through two locks in flight
from 55 feet above sea-level to the sea-level
channel on the Pacific side, steaming out through
this channel from the foot of the locks at Mira-
flores to deep water in the Pacific, a distance of
8 miles.
The total length of the Canal is 50' miles and
the time for passing through from one ocean to
the other will be from ten to twelve hours, ac-
cording to the speed a vessel maintains in the
lake area. Three hours of this time are taken up
in passing through the six locks. Of the total
length of the Canal, 40 miles will be of sufficient
width to allow vessels to go at practically full
speed, there being 15 miles of sea-level channel,
7 on one side and 8 on the other, and 25 miles of
open lake navigation in the two lakes, in all of
which the minimum channel width is to be 500
feet, and the maximum 1,000 feet. This leaves








only 101 miles which is at all narrow, 9 miles
being in the Cut where the bottom width is to be
300 feet and through which vessels will go at a
reduced rate of speed, and the remainder being
through the locks, where the vessel will be towed
by means of electric towing engines. Everywhere
except through the locks vessels will go under
their own power.


OCEAN LEVELS.

The general conception seems to be that the
Pacific Ocean is higher than the Atlantic; this,
however, is not the case. Mean sea-level, the
point midway between extreme high and low tide,
is exactly the same in both the Atlantic and the
Pacific. The difference is all in the tides. There
is an average tide on the Pacific of 20 feet, while
there are approximately but 20 inches of tide on
the Atlantic side.
This excessively high tide on the Pacific side is
apparently due to the shape of the Bay of Panama,
which, being shaped like a funnel, tends to exag-
gerate the action of the tide. The same thing
occurs at several other points throughout the
world, the most remarkable case being the Bay
of Fundy in Nova Scotia, where the tide sometimes
rises and falls 60 feet.











































FLAT ARCH IN THE CHURCH OF SAN DOMINGO, PANAMA.
This arch stands in the ruin of the Old San Domingo Church which was destroyed by fire in
1756. It spans 50 feet, is 35 feet high at the crown and 33 feet at the spring. The question as
to whether Panama is subject to severe earthquakes is frequently asked, and the fact that
this arch has stood for over 150 years is in itself practically an answer to that question.









BREAKWATERS.


Breakwaters are being constructed on both
the Pacific and the Atlantic sides. The one on
the Pacific end is simply an extension of a large
dump at East Balboa of material excavated from
the Culebra Cut, connecting Naos Island with the
mainland and designed to cut off a cross-current
which comes in at right angles to the line of the
Canal. This current although moving slowly
carries an enormous amount of silt and sand, and
it was to prevent the filling in of the sea-level
portion of the Canal that this breakwater was
constructed.
The Toro Point breakwater on the Atlantic side
extends northeast from Toro Point a distance of
11,000 feet and is designed to protect the Bay of
Limon from heavy storms which occur during
the winter months and are commonly known as
Northers. These storms are of such violence
that when one occurs vessels cannot lie at the
docks at Cristobal and Colon, but are forced to
move out into deep water to seek shelter farther
down the coast in the land-locked harbor of Porto
Bello. In addition to this breakwater a mole is
being built in connection with the dock improve-
ment work at Cristobal, behind which the docks
will be constructed. If it should be found after
this mole is completed that still further protection
is required then a second breakwater will be ex-
tended from the headland opposite Toro Point.







A


OLD FRENCH LOCOMOTIVES, NEAR EMPIRE, CANAL ZONE.










FRENCH WORK.

Active work was started by the French on their
Canal in 1881, and this first French Company, which
was organized by De Lesseps, failed during the
latter part of 1888 after spending $260,000,000.00.
For five years the company remained in the hands
of a receiver, and in 1894 the New French Com-
pany was organized and kept up the work on a
very small scale until 1904 when the United
States took over the construction.
The plan of this last French Company was to
build a lock type canal with a total of eight locks
and a summit level through the Culebra Cut at
97 feet above sea-level. Starting just behind
Cristobal Point, in order to secure the protection
of that point against the Northers, and extending
for 16 miles inland to Bohio, the Canal was to
be a sea-level type. At Bohio a dam and two
locks were to be located, forming the Bohio Lake
with a surface level of 65 feet above sea-level.
Passing through this lake a distance of 14 miles
the vessels would arrive at Bas Obispo at the
northern end of the Cut, where it was intended
to locate two more locks with a combined lift
of 32 feet. In order to secure water for the sum-
mit level through the Cut it would have been
necessary to build an additional reservoir at
Alhajuela farther up the valley of the Chagres,
bringing a ditch line along the hillsides from this
lake down and into the Cut. Passing through
[17]







































ABANDONED FRENCH LADDER DREDGES.


:- ^_'*/- ..1 "s^- + 'ni

-.Si ...... \. ',.B .








the Cut, vessels were to be lowered to the Pacific
through four locks, one at Paraiso, two at Pedro
Miguel, and one at Miraflores, from which point
a sea-level canal 8 miles long led out into deep
water in the Pacific.


FRENCH PURCHASE.

The rights and property of this French Company
were purchased by the United States for $40,000,-
000.00; and up to date our country has realized
on this purchase, on a very conservative estimate,
over forty-two million dollars.
Out of 80,000,000 cubic yards of excavation
work which the French Company had done only
30,000,000 yards were useful in the construction
of the present type of Canal, and in estimating
the value of the French purchase an allowance
of $25,389,240.00 was made for this excavation
work. It had cost approximately one hundred
and twenty million dollars.
The value of the Panama Railroad was esti-
mated at $9,000,000.00. This railroad was ac-
quired by the French at a cost of $18,000,000.00.
In addition to these two main items the purchase
included a great deal of machinery, and the
Commission is today using 85 French loco-
motives and 7 ladder dredges included in the
property purchased. The French also turned over
a great many buildings, maps, and scientific
data, including records of the flow of the Chagres









River through a period of 15 years. On these
records it is impossible to place any cash value,
as they would not have been available at any
price, had not the French kept these records,
and with the present type of canal it is a matter
of vital importance to be able to estimate ac-
curately the volume of the flow of the Chagres,
as it is the Chagres that supplies the water to
fill the Gatun Lake and make the lockages through
the Canal. Now, due to the fact that we have
secured these French records, we have a com-
plete record of the flow of the Chagres extending
through a period of twenty-three years.


RELOCATION OF PANAMA
RAILROAD.

As the construction of the Canal progressed
it became necessary from time to time to aban-
don small sections of the original Panama Rail-
road line, which was built in 1850 by three
Americans, Aspinwall, Stephens, and Chauncey.
In 1908, the section between Mindi and Tiger
Hill was relocated as the old line passed right
through the site of the Gatun Dam and Locks.
In 1910, the section between Pedro Miguel and
Corozal was relocated, establishing the line per-
manently at an elevation sufficiently high to be
above the level of Miraflores Lake, and on Feb-
ruary 15, 1912, the relocated line between Gatun
and Matachin was put into service, as the rising
[20]









water of the Gatun Lake due to the closing up
of the Chagres at Gatun on February 9, soon
flooded most of the old line between these points.
The Gatun Lake now stands 50 feet above sea-
level, at which elevation it floods the old railroad
right of way to about Tabernilla and covers an
area of over 90 square miles.
Finally, with the Canal completed, a new rail-
road will have been constructed, running from
Colon to Panama entirely on the east side of the
Canal. The new road after leaving Gatun swings
east along the hillsides, and crossing through the
lake on high earth fills, follows the borders of the
lake to Gamboa, where it crosses the Chagres on
a steel girder bridge a quarter of a mile long.
From here it swings away from the Cut and,
passing around back of Gold Hill, follows the
Pedro Miguel valley to Pedro Miguel. Originally
it was intended to carry the railroad through the
Cut on a bench 10 feet above the water, but the
slides in the Cut made that impracticable.

GATUN DAM AND LAKE
The Gatun Dam is a huge earth structure and
is, in fact, more of a mountain than a dam. It
is so constructed as to complete the natural range
of mountains which, excepting at this one point,
entirely surround the low-lying basin of the
Chagres. By completing this basin, it is possible
to retain the waters of the Chagres and thereby
form the Gatun Lake.

























--,


OLD FRENCH EXCAVATION IN CUT NEAR EMPIRE.









The dam is constructed of two outer walls of
dry fill, a large part of which was excavated from
the Culebra Cut. These two walls, or toes, as
they are usually called, were constructed so as
to be 1,200 feet apart (inside measurement) and
this space in between the two walls was filled
with a mixture of sand and clay which was sucked
up from the river bed of the Chagres, both above
and below the dam, by means of large suction
dredges and then pumped through long pipe lines
into the space between the two walls of dry earth
fill. About 20 per cent of the material passing
through these pipe lines was solid matter, the bal-
ance water. After the solid matter settled the sur-
plus water was drained off and in that way the
inner portion of the dam was built up. This inner
core is usually known as the hydraulic core and
forms the watertight portion of the dam. After
the hydraulic core had been carried a short way
above the water level it was discontinued and the
outer walls were then carried higher and closer
together until they entirely encased and capped
over the inner core.
The Gatun Dam at the base is 2,100 feet, or
about a half mile thick, 400 feet thick at the water
surface, and 100 feet wide across the crest. The
crest of the dam stands 105 feet above sea-level
and 20 feet above the surface of the water of the
lake. The length of the dam measured along
the crest is 7,500 feet, but of this length only 500
feet will be subject to the full pressure of 85 feet
[23]








of water, due to the natural rise of the ground
along the inner slopes of the dam.
In connection with this dam it is interesting
to know that a Frenchman named Lepinay was
the first to propose the plan of constructing a
dam at Gatun. He proposed this plan in 1879
to the International Scientific Congress which had
been convened at Paris to determine upon the
general route of the proposed canal, but De Les-
seps, who was the leading spirit of this Congress,
was so strong an advocate of the sea-level canal
that Lepinay's plan was hardly discussed, and is
simply a matter of record.


SPILLWAY.

The spillway, which is located about midway
of the dam, is built right into a natural hill, which
stood at an elevation of 110 feet above sea-level.
This hill was practically solid rock, so it was only
necessary to cut a channel 300 feet wide through
this hill and line it with concrete, building a dam
across the head of this channel to form the spill-
way or regulating works for Gatun Lake. This
dam forms nearly a semicircle across the head
of the spillway channel and will be constructed
of solid concrete up to elevation 69. At this level
piers rise 45 feet apart on the crest of the solid
portion of the dam, and in between these piers
come the steel gates nineteen feet high which
control the level of the lake.
[24]








With these gates closed, the crest of the dam
would be 88 feet above sea-level, so that it would
be possible to store up water in the Gatun Lake
up to about 87 feet above sea-level. The normal
level of the lake is to be 85 feet and it will be
maintained at that level during most of the year;
just at the last of the rainy season, however, the
lake level will be brought up to 87 in order to
supply the water for lockages during the dry
season. This will give an additional two feet
of water over an area of 164 square miles, which
would be sufficient to make 58 lockages a day
during the dry season; that is, ten more than
could possibly be made with vessels following
one another at intervals of one hour.
With the lake at 85 the spillway will be capable
of discharging 154,000 cubic feet per second,
which is more than the greatest momentary
discharge on the Chagres River at Gatun.
If the Gatun Lake should ever go to elevation
92 the spillway would be capable of discharging
over 200,000 cubic feet of water per second, which
is very nearly equal to the discharge of the Horse-
shoe Falls at Niagara. In addition to the control
of the Chagres effected by means of the spillway,
there is the great reservoiring effect of the Gatun
Lake, it being of such great area that it would take
the greatest known flood of the Chagres River
nine hours to raise the level of the lake one foot,
even though no water was discharging through
the spillway at Gatun.








WATER SUPPLY.

To those who are skeptical as to the supply of
water which will be available to fill the Gatun
Lake the following figures may be of interest.
The rainy season on the Isthmus usually ex-
tends through the last eight months of the year
and the remaining four months make up the dry
season.
At Colon the average annual rainfall amounts
to 130 inches a year and, as one comes across
the Isthmus from Colon to Panama, the rainfall
decreases gradually until at Panama the rain-
fall averages 70 inches per annum. Now, as
one goes east and west from the Zone, one
gets into sections that are more mountainous in
which it rains almost every day in the year, so that
at Porto Bello one finds an annual average rain-
fall of 173 inches. In 1909 Porto Bello had 237
inches of rain; during one month of that year
it had 58 inches, or more than the average
annual rainfall around New York or Boston, which
is 40-45 inches.
Porto Bello also holds the record for 24 hours'
rainfall, which amounted to 10.86 inches. The
greatest recorded rainfall for one hour is 5.86
inches at Balboa in June, 1906. The heaviest
rainfall of short duration occurred at Porto Bello
in December, 1911, amounting to 2.46 inches in
three minutes.
The area drained by the Chagres and its tribu-
taries is 1,320 square miles, and in 1910 the volume
[26]








of the discharge of that river at Gatun equaled
once and a half the volume of water that will be
contained in the Gatun Lake. At Gamboa, the
river has been known to rise 40 feet in 24 hours
and to discharge 100 times the water that it does
in the dry season, amounting during one flood to
a flow of 170,000 cubic feet per second, which
equals two-thirds of the volume of water which
passes over the Horseshoe Falls at Niagara.

POWER PLANTS.
On the east side of the spillway will be located
a large hydro-electric plant. This plant will take
water from the Gatun Lake, pass it through tur-
bines and discharge it through openings in the
side wall of the spillway channel, thereby generat-
ing all the power necessary to operate the lock
machinery throughout the entire length of the
Canal. This plant consists of three 2,000 kilowatt
generators, one of which is a reserve, producing
ordinarily over 5,000 horse power with a reserve
of 2,500 horse power.
The fall from the level of Gatun Lake to the
level of the spillway floor being 75 feet, the supply
of water for operating this plant will be ample at
all times of the year.
As an extra precaution, however, the present
6,000 horse power construction plant at Miraflores,
which is an oil-burning steam plant, will be re-
tained as an auxiliary to the Gatun plant should
it ever be needed.

















- I-;


- a


STEAM SHOVEL LOADING ROCK FOR THE TORO POINT BREAKWATER.









CULEBRA CUT.
The Culebra Cut, from which it was necessary
to excavate over 105,000,000 cubic yards of rock
and earth, representing nearly half of the excava-
tion work on the entire Canal, begins at the point
where the Canal leaves the valley of the Chagres
near Bas Obispo and follows the winding valley
of the Rio Obispo until it reaches the Continental
Divide near Culebra. After cutting through the
divide it follows the valley of the Rio Grande to
Pedro Miguel.
The Cut is nine miles long and will be 300 feet
wide on the bottom. At all the angles it is widened
out sufficiently to allow a vessel 1,000 feet long
to make the turn with perfect ease. The average
depth to which it was necessary to excavate below
the natural surface was approximately 120 feet
through the entire length of the Cut. At the
point where the Continental Divide was severed
between Gold Hill and Contractor's Hill the
cutting will average 375 feet.

EXCAVATION.
On January 1, 1913, there remained to be exca-
vated throughout the Cut 5,501,419 cubic yards of
material. In the year 1911, 16,600,000 cubic yards
were excavated, so that at this time there remains
to be taken out less material than was excavated
in the past twelve months. The 5,501,419 cubic
yards which are still to be excavated lie in the
[29]









Cut in the shape of a mount 4 miles long at the
base and 25 feet high. At the highest point,
this summit is located just opposite Culebra, and
the mound slopes both ways from that level, so
that on either end of the Cut a point is reached
where the excavation work has been carried
down to the final grade. Thirty-eight steam
shovels are at work excavating this material,
each one taking out on an average 1,500 cubic
yards of rock and earth each day. Records
have been made, however, of over 4,000 cubic
yards in eight hours. As a matter of fact, the
number of hours that a steam shovel is generally
employed in loading cars amounts to only about
six, as the problem in the Cut is more one of
transportation than of excavation, and it is not
possible to keep trains standing under the shovels
more than six hours out of the eight. All told,
there are now about 75 miles of track in the Cut,
of which it is necessary to move about a mile each
day. At the present time, about 150 loaded
trains of earth are passing out of the Cut daily,
but at the time when the excavation work was at
its maximum 175 trains were leaving each day,
which amounted to about one train every two and
one-half minutes. The monthly output from the
Cut reaches close to 1,500,000 cubic yards.
The buckets used on most of the shovels in the
Cut load 4 and 5 cubic yards at a time, which by
weight means from 6 to 7Y2 tons to the bucketful.









DRILLING AND BLASTING.

All of the material which is excavated by the
shovels is first drilled and then blasted before
it can be handled, and in the length of the Cut
a great number of drills are constantly working.
All of these drills, of which there are two styles,
churn and tripod, are operated by compressed
air supplied from one long air main which par-
allels the line of the Cut. Three compressor
plants are pumping into this line, one located
near the middle and one near each end of the
line. The average depth to which the holes are
drilled is 24 feet, and after drilling to this depth
a small charge of dynamite is placed in the hole
and discharged by means of the magneto battery,
enlarging in that way the size of the hole at the
bottom. Then, after the hole has cooled off it
is ready to receive the large charge of dynamite
varying from 75 to 200 pounds to each hole. This
charge is exploded by means of the regular
electric light current, the ordinary magneto bat-
tery having been found too unreliable and its use
resulted in too many misfired shots, which had
to be subsequently excavated, thereby greatly
endangering the lives of the workmen.
Each month an average of 75 miles of drill
holes are sunk, and if all the drill holes which
have been put down since the United States has
been at work were placed end to end the hole
would pass entirely through the earth, coming
[31]








































STEAM SHOVEL IN CULEBRA CUT, BURIED UNDER SMALL ROCK SLIDE, MAY 31, 1912.
STEAM SIHOVEL IN CUTLEIlRA CUT. BURIED UNDER SMALL ROCK SLIDE, MIAY 31, 1912.









out in the Indian Ocean south of the Island of
Sumatra. Five hundred thousand pounds of
dynamite are used each month in the Cut, and on
the entire Canal 800,000 pounds are consumed.


SLIDES.

At the present time, there are in the length
of the Cut nineteen slides varying greatly in size,
the total area involved amounting to 210 acres.
One of the largest is the Cucaracha slide just
south of Gold Hill, which started during the
French time and now covers an area of 47 acres,
and is broken back a distance of 1,800 feet from
the center line of the Cut. A great number of
smaller slides have occurred throughout the Cut,
the worst section for slides being right around
the town of Culebra. From time to time small
slides have occurred here on both the east and
west banks, which have gradually combined,
forming two large slides, until they have become
more difficult to handle than the Cucaracha slide.
Two general characters of slides are found in
the Cut. One is the true slide, which is a mass
of earth that is sliding from a hard surface that
pitches towards the Cut and this slide is glacial in
its action. There are no means of overcoming or
correcting this character of slide; the only thing that
can be done is to take the material out as it slides
in and continue to do so until the sliding material
reaches an angle flat enough to stand. The other
[33]












.7 f,


h-.-M


SLIDE OF 300,000 CUBIC YARDS IN THE EAST BANK OF CULEBRA CUT, AUGUST 21, 1912.


ak.








is a slide that is caused by the great weight of the
banks on either side of the Cut weighting down
and squeezing out the soft underlying strata,
which in giving away bulge up at the bottom
of the Cut, allowing the banks on either side to
settle. These banks in settling break loose and
begin to move toward the Cut. The first move-
ment of the banks in this kind of slide is down-
ward and then the lateral motion follows. The
slides near Culebra are of this type. In order
to correct this character of slide steam shovels
are working on top of the banks, taking material
off the top, thereby reducing the weight of the
banks and to a certain extent preventing further
sliding.

DIVERSION CHANNELS.
As the Cut follows the valleys of the Rio Obispo
and Rio Grande, it was necessary to divert these
streams and their main tributaries to prevent the
Cut from being flooded during the rainy season.
So that paralleling the line of the Cut on the west
side we have the Rio Grande and Comacho diver-
sions, and on the east side the Obispo diversion.
These diversion channels parallel the line of the
Cut and carry off the water of these small streams
as well as a large part of the surface drainage
water, thus preventing the flooding of the Cut
itself. These channels were all started by the
French, but were enlarged after the United States
began work on the Canal.
[35]













































GATUN LOCKS IN COURSE OF CONSTRUCTION.









LOCKS.

There are six locks in the Canal, three in flight
at Gatun, one at Pedro Miguel and two in flight
at Miraflores. All locks are constructed in pairs,
so that vessels can go in opposite directions at
the same time. Each Jock or flight of locks is in
general to be reserved for ships going in one
direction, the twin lock or flight being used for
vessels going in the opposite direction.
The length of the lock chamber is 1,000 feet,
the width 110 feet, and the depth of water over
the sills 41'3- feet in fresh water and 40 feet in
salt water.
The Pedro Miguel Lock is the same in all the
essential features as the other locks and as there
is only one lift at this point it is the best one to
describe.
A simple definition of a lock is a walled chamber
between two bodies of water of different levels
having gates at either end, in which it is possible
to confine vessels while they are being raised or
lowered from one level to another by allowing
water to flow in or out of the lock chamber.
The method of raising or lowering the level of
the water in the lock chamber varies on different
lock canals. The lock chambers on most of the
old canals are emptied or filled through sluice
gates that slide up and down in the lock gates
themselves. This system, however, caused a
great deal of surging of the water at that end of








the lock at which it was flowing in or out, and the
system that has been adopted on the Panama
Canal was designed with the idea of avoiding this
disturbance of the water in the lock.
All the locks on the Panama Canal have two
parallel lock chambers separated by a center wall.
The water is brought in or out of these chambers
through huge tunnels 18 feet in diameter passing
lengthwise of the lock through the center and side
walls. Branching out from these tunnels at
right angles and running out under the lock floor
are laterals and these laterals communicate with
the lock chamber through openings in the lock
floor. The flow of water in or out of the lock
is controlled by the gate valves located at both
the upper and lower ends of the feed tunnels. In
order to raise the water in the lock chamber the
valves at the lower end are closed and the ones
at the upper end opened. The water then flows
from the upper level into the lock, passing down
the tunnel in the side wall and out through the
laterals under the floor, coming up through the
openings in the floor. It continues to flow in
this way until the elevation of the water in the
lock chamber is the same as that of the water
above. To lower the water in the lock the pro-
cess is simply reversed. The upper valves are
closed and the lower ones opened. The water
then flows out from the lock chamber and passing
back through the same tunnels that brought it in
seeks the level of the water below. So that, in









order to raise a vessel from one level to another,
the level of the water in the lock chamber is
brought to the same level as that at which the
vessel stands. The lock gates are then opened,
the vessel passes into the chamber and the gates
are closed. Water is then allowed to flow into
the lock until the vessel is raised to the level of
the upper body of water, and with the same level
on both sides of the upper gates those gates are
thrown open, the vessel passing out at a greater
elevation than that at which it entered the lock.
The big tunnels passing through the side walls
are the main operating tunnels, the one through
the center wall being an auxiliary used to assist
in filling the lock during the latter part of the opera-
tion, thereby increasing the volume of the inflow
at the time when the velocity of the water entering
the lock from the side wall tunnels is decreasing,
keeping up in that way an average rate of filling
which would amount to about 2 feet per minute.
So that, at Pedro Miguel, where the lift is 30 feet,
a vessel would be raised from one level to the
other in 15 minutes. The desired rate of filling
can be kept up for the 600-foot and 400-foot locks
by the side culvert only. It is probable that the
center wall tunnel will be used only in case of the
1000-foot lockages.
From the center wall tunnel laterals, which alter-
nate with laterals from the side walls, lead out
under the floors of both lock chambers. They
are controlled, independent of the main tunnel,























. ,y


CROSS-SECTION OF LOCK CHAMBER AND WALLS, GATUN LOCKS.
A. Culvert in center wall. E. Culvert in side wall.
B. Connections between center and lateral culvert. F. Drainage gallery.
C. Lateral culvert. G. Gallery for electric wires.
D. Wells opening from lateral culverts into lock chamber. H. Passageway for operators.









by cylindrical valves located at the head of each
tunnel, so that it is possible to close the laterals
all the way down on one side, opening those on
the other side, and feed water to one lock chamber;
or, by reversing the process, feed water to the
other chamber. By opening the valves to the
laterals on both sides itis possible to pass water
through from one chamber to the other, in that
way effecting a saving of water whenever vessels
are going in opposite directions at the same time.
Another means of economizing water is by
using the intermediate lock gate which divides
the 1000-foot lock into two sections of 600 and
400 feet, respectively; so that in putting through
small vessels it is not necessary to fill or empty
the entire chamber.


ELECTRIC LOCOMOTIVES.

The protective devices are one of the most
interesting features of the lock construction, and
of these the electric locomotives are the most
important. About ninety per cent of all accidents
to other locks have been due to misunderstanding
in signals between the captain and engineer of
the vessel, and all accidents of that kind will be
eliminated by requiring vessels to go through the
locks in tow of electric locomotives operating on
the center and side walls of the locks. A vessel
comes in and ties up to the center wall, which
is extended beyond the side walls at both the















i-.. ;
Ti'l ":a-a.^,'- m.. li^


ENTRANCE TO UPPER GATUN LOCK FROM THE LAKE.








upper and lower ends of the lock simply to act as
a wharf or mooring wall. The vessel waits here
until the locomotives come down and tow it up
to a point where the locomotives on the side walls
make fast their lines. The vessel then goes into
the lock chamber with two locomotives in front
towing, one on either side', and two others behind
to retard when she gets into proper position.
These towing locomotives operate on tracks
close to the edge of the wall and engage in a
center cog rail. While running on this cog rail
the maximum speed at which they can operate
will be two miles per hour. When they have
completed a tow, however, they switch over to
a track farther back from the edge of the wall
and here the cog rail is omitted, so that they can
return at a greater speed.

PROTECTIVE CHAIN.
Should a vessel not obey the order to stop out
alongside the center wall but come ahead, it
first would encounter a chain stretched across
the entrance to the lock chamber. This chain
connects on either side with large hydraulic
cylinders located in shafts in the lock walls. The
pressure from these cylinders causes the chain
as it plays out to offer more and more resistance
to the motion of the vessel. The chain is capable
of stopping in 70 feet a 10,000-ton vessel running
four miles per hour. The stock from which it
is to be forged is three inches in diameter.









2~


I


N
-l ~t.l
U H
9, 'I


GENERAL VIEW OF THE PEDRO MIGUEL LOCK









When not in use the cylinders are forced up
and the weight of the chain carries it down into
the groove in the bottom of the lock floor and the
vessel passes over it.

GUARD GATES.
If a vessel should break through the fender-
chain, it would then ram the lock gate, but with
this contingency in view two gates instead of one
have been provided at the upper and lower ends
of the highest lock in each flight, the upper or
guard gate of each pair serving to protect the
lower gate from ramming. Both gates would have
to be broken down to put the lock out of commis-
sion.
LOWER GUARD GATE.

At the lower end of all the sets of locks a small
guard gate has been put in, mitering the other
way from the main lock gates, which miter to-
wards the high level, and it has been designed to
serve two purposes: first, as a coffer gate or
dam, if at any time it is necessary to pump the
water from the lower lock chamber; second,
as a guard gate to the lower lock gate, for, miter-
ing as it does, it will stand a heavier blow from
the lower side than the lock gate itself.

EMERGENCY DAM.
If all of these devices should fail and there
should be an accident which would establish
[45]









free communication between the two levels
above and below a lock, a most destructive
accident would be the result, for the velocity
of the water flowing through the lock chamber
would be 24 feet per second and the discharge
would amount to 90,000 cubic feet per second.
In order to shut off this water and prevent it
from tearing out the lock floor it is necessary to
employ a device known as an emergency dam, of
which there are two installed at the upper end
of each set of locks, one for either side. These
resemble a swing bridge and when put into use
they are swung out across the lock and from their
lower side a set of open-work wickets are lowered,
engaging in a grooved sill on the lock floor. When
these wickets are down and in place, small plates
resembling little flat cars are allowed to run down,
one on each wicket, building up a row of plates
across the bottom, one joining the other. When
the first complete set has been let down nine
feet of the water will be shut off, and then an-
other set of plates will be let down, until finally
the water rushing through the lock will be entirely
shut off. Of course, there will be some seepage
through the plates, but the water above this tem-
porary dam will be still water and the electric
locomotives will go down and take in tow a floating
caisson, or hollow steel float, and towing it around
seat it against a sill at the upper end of the lock
chamber. Then by filling water into the caisson
it is sunk, entirely shutting off the water flowing
[46]








through the lock. The emergency dam is then
raised and the necessary repairs made to the
locks.
LOCK GATES.
The construction of the lock gates is also inter-
esting. They were built up of big horizontal
girders weighing from 12 to 18 tons each, with
vertical framework in between and sheathing
plate both on the inside and outside of this frame.
They are cellular in construction and the lower
half of the gate is an air chamber which supports
about three-quarters of the weight of the gate
when submerged. The upper half of the gate is
arranged with openings in the plates on the up-
stream side so that water can flow in or out of the
upper half of the gate at the same time that it
flows in and out of the lock, increasing the
weight of the gate as the height of the water on
the outside increases, overcoming in that way the
lifting effect of the air chamber in the bottom of
the gate as it is placed deeper and deeper under
water.
These gates vary in height from 47 to 82 feet,
and in weight from 300 to 700 tons to each half
gate. If each half gate were laid flat one on top
of the other they would build up a tower contain-
ing 58,000 tons of steel standing 32 feet higher than
the Singer Building in New York. There are
92 half gates and each is seven feet in thickness
Another interesting comparative figure is one
pertaining to the excavated material. All of the
[47]













































SANITARY DRIP BARREL.
Placed at the headwaters of a stream, these barrels automatically feed crude oil, which
spreads out over the surface of the water.








excavated material which will have been taken
out when the Canal is completed, including the
30,000,000 cubic yards of useful French excava-
tion, if loaded on one train of flat cars similar to
the wooden cars one sees commonly on the
work, would make a train over 110,000 miles long,
reaching more than four times around the earth.


SANITATION.

No one single factor has been more important
in making the construction of this Canal a pos-
sibility than that of sanitation. One of the
worst snags that the French ran against was this
very question of sanitation. Unfortunately, there
are no accurate figures obtainable on the lives
lost during the French time; the only figure
available is for the mortality in Ancon Hospital,
which for the eight years between 1881 and 1888
amounted to 5,527. But the French were, at this
time, doing their work by contract and each con-
tractor was charged a dollar per day for each
man he had in hospital. It will readily be under-
stood, therefore, that if the French contractor
were anything like the ordinary contractor, not a
very large proportion of the sick would go to this
hospital. We hear of many individual instances
of heavy loss. The first French director, Mr.
Dingler, came to the Isthmus with his wife and
three children. At the end of the first six
months all had died of yellow fever except him-









self. One of the French engineers, who was
still on the Isthmus when we first arrived, stated
that he came over with a party of seventeen
young Frenchmen. In a month they had all
died of yellow fever except himself. The super-
intendent of the railroad brought to the Isthmus
his three sisters; within a month they had all
died of yellow fever. The Mother Superior of
the sisters nursing in Ancon Hospital told me
that she had come out with twenty-four sisters.
Within a few years twenty-one had died, the
most of yellow fever. Many other instances of
this kind could be cited. During the eight years
that the Americans have been at work on the
Canal the death roll has reached 5,141, of which
995 have been deaths from violence. For the
fiscal year 1912 the death rate per thousand on the
Isthmus was lower than in almost any large city
in the United States, as the following figures will
show:

Deaths from accidents........... 3.08
Deaths from diseases ....... .... 7.08

Total deaths from all causes....... 10.16

The most important work of the Sanitary
Department and the one which has had most to
do with the reduction of the death rate is undoubt-
edly that which has to do with the control of the
breeding of mosquitoes, so that I will speak only
of that one feature of its work.
[501








I have found it a very prevalent idea among the
visitors to the Isthmus that the mosquitoes have
been entirely exterminated from the Zone; such,
however, is not the case, for, although there are
448 square miles within the Zone, the destruction
of the mosquito is carried on over only about 100
square miles. Outside of this area of 100 square
miles mosquitoes can be found just as thick as they
ever were; but, by constant vigilance and effort,
the number of mosquitoes in the sanitated areas
has been reduced to such a very few that adult
mosquitoes are but seldom seen by the casual
observer.
For the purpose of sanitation, the Zone is
divided into sanitary districts, each district being
placed in charge of a sanitary inspector. As a
general rule, the sanitary work is carried on to a
distance of about 1,000 yards outside the extreme
limits of any inhabited district, as this has been
found to be about the flying radius of the varieties
of mosquitoes which the Sanitary Department has
to deal with. The work of controlling the mos-
quitoes within these districts falls under three
heads:
FIRST: Elimination of favorable breeding
places by filling, drainage, removal of grass to
favor evaporation, clearing of banks of streams
and other bodies of water to give access to fish
that eat the larvae of the mosquitoes, removal
of vegetation and other foreign matter such as
algae which gives shelter to the larvae of the








mosquitoes, introduction of water supplies to
reduce the number of water-holding containers
in which the yellow-fever mosquito breeds, and
screening of such water containers as cannot be
done away with.
SECOND: By oiling or larvaciding such
bodies of water as cannot be conveniently and
economically eliminated, the oil used for this
purpose being the ordinary crude oil and the
larvacide a mixture of creosote, caustic soda and
resin.
THIRD: By preventing the access of mos-
quitoes to the inhabitants by effectively screening
as many dwellings as possible and, in addition,
by catching in specially designed traps and by
hand such mosquitoes as find their way into
dwellings.
By the constant application of these methods the
malaria rate has been reduced from about 6.83 %
of employees admitted each month to the hospital
in 1906 to about 1% per month for the current
year, and in totally eliminating yellow fever from
the cities of Panama and Colon and the Canal
Zone, the last case of this disease having occurred
in Colon in May, 1906.









INTERESTING FACTS AND
FIGURES

Length of Canal from deep water to
deep water (miles) ............... 5012
Length from shore-line to shore-line
(m iles) .......... .. ........... 40
Time of transit through completed
Canal (hours)................... 10 to 12
Time of passage through locks (hours) 3
Bottom width of channel, maximum
(feet) ........... ..... ......... 1,000
Bottom width of channel, minimum, 9
miles Culebra Cut (feet) .......... 300
Locks, in pairs ..................... 12
Locks, usable length (feet) ........... 1,000
Locks, usable width (feet) ........... 110
Gatun Lake, area (square miles) ...... 164
Gatun Lake, channel depth (feet)... 85 to 45
Culebra Cut, channel depth (feet) ..... 45
Excavation, estimated total (cubic
yards) ............ ......... 212,504,138
Excavation, amount accomplished to
January 1, 1913 (cubic yards) .....188,280,312
Excavation by the French (cubic yards) 78,146,960
Excavation by French, useful to pres-
ent Canal (cubic yards)........... 29,908,000
Excavation by French, estimated value
to Canal . ........ ........... $25,389,240
Value of all French property ....... $42,799,826
Concrete, total estimated for Canal
(cubic yards) . . . . .... 5,000,000








Weight of one cubic yard of concrete
or earth (pounds) ................. 3,000
Relocated Panama Railroad, estimated
cost....................... $9,000,000
Relocated Panama Railroad, length
(m iles) ....................... 47.1
Maximum grade on Panama Railroad
(per cent) ....................... 1.25
Maximum curve on Panama Railroad
(degrees) .......... ............. 7
Gage of Panama Railroad (feet) . 5
Canal Zone, area (square miles) ...... 448
Canal and Panama Railroad force
actually at work (about) ........... 35,000
Canal and Panama Railroad force,
Americans (about) ........ 5,000
Cost of Canal, estimated total ....... $375,000,000
Amount spent by French ............ $260,000,000
Work begun by Americans ......... May 4, 1904
Date of official opening ............. Jan. 1, 1915
Population of Colon................ 17,740
Population of Panama City ......... 37,505
Tide on Pacific side (feet) .......... 20
Tide on Atlantic side (inches) ....... 26
Area drained by the Chagres River
(square miles) ......... ......... 1,320
Average rainfall at Colon (inches)... 130
Average rainfall at Panama (inches) 70
Average rainfall at Porto Bello
(inches) ....................... 173
Maximum rainfall of record for 3
minutes (inches)......... ... .... 2.46
[54]









Maximum rainfall of record for 1 hour
(inches) ....................... 5.86
Maximum rainfall of record for 24
hours (inches) .................. 10.86
Maximum temperature of record (de-
grees fahr.) .................... 96.6
Minimum temperature of record (de-
grees fahr.) .................... 59
Average mean temperature......... 79
Mean relative humidity (per cent) 89
Evaporation per annum (inches) ..... 52
Maximum momentary discharge of
Chagres at Gamboa (cubic feet per
second) ....... ............. 170,000
Volume of water passing over the
Horseshoe Falls at Niagara (cubic
feet per second) .. . .. 250,000
Average amount excavated in 8 hours
by each steam shovel in Cut (cubic
yards) ............. ... ...... .. 1,500
Record for 8 hours for steam shovels
of any class (cubic yards) ......... 5,554
Record for 8 hours for 70-ton shovels,
3-yard bucket (cubic yards) ....... 3,910
Location of Rock Crushers and Sand
Pits:
Atlantic Side:
Rock Quarry, Porto Bello, capa-
city, cubic yards per day ..... 3,000
Sand Pits, Nombre de Dios.
Pacific Side:
Rock Quarry, Ancon Hill, capa-
city, cubic yards per day ...... 2,000
Sand Pits, Point Chame.
[55]









Amount of oil used per month (barrels) 75,000
Cost of same (per barrel) ........... $1.10
Amount of coal used per month (tons) 35,000
Cost of same, delivered in fire-box
(per ton) ......... .......... $6.00
Number of miles of track on Isthmus
(about) ............... ....... 500
Death rate per thousand, 1912:
Accidents ...................... 3.08
Disease ....................... 7.08

Total from all causes ...... 10.16



EQUIPMENT.

Steam Shovels:
105-ton, 5 cubic yard dippers...... 15
95-ton, 4 and 5 cubic yard dippers. 32
70-ton, 2Y2 and 3 cubic yard dippers 35
66-ton, 22 cubic yard dippers..... 6
45-ton, 1% cubic yard dippers..... 10
26-ton ........... .. ....... 1
Trenching shovel, Y cubic yard
dipper.......... ... ...... 1

T otal ........... ........... 100

Cranes:
Am erican.......... .......... 60
French .............. ....... 9

T otal........................ 69








Locomotives:
American
106 tons .......... ......... 100
105tons ................... 40
117 tons........... ........ 20

Total ...................... 160


French
20 tons ....... ... ... ........ 5
28 tons .......... .......... 20
30 tons ........ .. .......... 16
38 tons........ .. .......... 36.
Decauville.............. 8

T otal ...................... 85


Narrow gauge, American, 40 tons. 10
Narrow gauge, American, 16 tons. 23
Electric ......... ........ 12

T otal .......... ........... ... 45

Grand total ..... . 290


Drills:
Mechanical churn, or well....... 265
Tripod ..................... 361

Total ........................ 626

[57]









Cars:
Flat, used with unloading plows .. 1,800
Steel dumps, large .. . . 600
Steel dumps, small .............. 1,200
Ballast dumps, steel ........... 12
Ballast dumps, wood ............ 12
Steel flats.......... ......... 500
Narrow gauge ...... ........... 200
M otor .... ... ...... ....... 6
Pay Car ........ ... ... ...... 1

Total ....... ..... ....... 4,331

Spreaders ....................... 26
Track shifters .................... 9
U nloaders ....... ...... .... ..... 26
Pile drivers ....... .... ........... 13


Dredges:
American ladder.......... 1
French ladder.......... ....... 7
Dipper .......... ..... ....... 3
Pipe-line .................... 7
Sea-going suction ............ 2
Clam shell ..................... 1

T otal ........................ 2 1

Rock breaker, floating ...... .... 1
T u gs ........................... 12
T ow boat ....... ........... ...... 1
H house boats...................... 2
[58]









C lapets .......................... 11
Pile driver, floating................ 1
Crane boat .............. ........ 1
Barges, lighters and scows .......... 70
Launches ........................ 14
C utters .......................... 3
D rill boats ...... ......... .... 2
Derrick barges................... 2


PANAMA RAILROAD.
Locomotives:
Road (12 oil burners)............ 36
Switch ............. ......... 34

T otal ........................ 70

Cars:
Coaches ........ .... ......... 57
Freight.................... 1,477

T otal ........ .............. 1,534

Locomotive cranes ................ 4
Pile driver, track .................. 1
Pile driver, floating ................ 1
T u g s . .. . . . .. .. .. 2

Lighters:
Coal, all steel.......... ....... 5
Cargo, steel and iron........ ..... 8

T otal ....... ..... ............ 13
[591






















A4 General Map of the Canal Zone
and the Panama Canal, printed in
three colors and bound in board
covers, has just been issued.


Size 4 x 13 inches, folded.


Published by Wm. M. Baxter, Jr.,
Official Guide of the Isthmian
Canal Commission.


M


RAND AVERY SUPPLY CS.. RDSTON.




Full Text

PAGE 2

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PAGE 3

THEPANAMACANALA BRIEF AND ,SIMPLE DESCRIPTIONOFTHEESSENTIAL FEATURESBYWILLIAMM.BAXTER,JR.TheOfficialGuide of the Isthmian Canal CommissionENLARGEDANDILLUSTRATED1913

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." ,,, .'COPYRIGHT,1913,BYWlII.M.JR...,.,""'.J.'-.

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LISTOFILLUSTRATIONS.PageCulebra Cut, looking north from the Continental Divide ........8 Flat Arch in the Church of San Domingo,Panama..........14Old French Locomotives,nearEmpire, Canal Zone .........16Abandoned French LadderDredges...18Old French Excavation in Cut,nearEmpire 22SteamShovel Loading Rock for the Toro Point Breakwater .......28SteamShovel in Culebra Cut, buried undersmall rock slide,May31, 1912 ... 32 Slide of 300,000 cubic yards in theEastBank of Culebra Cut, August21,1912 34 Gatun Locks in Course of Construction. .36Cross-section of Lock Chamber and Walls, Gatun Locks .........40Entrance to Upper Gatun Lock from theLake............ 42 General View of the Pedro Miguel Lock 44 Sanitary Drip Barrel ........48

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," .."'"",,,,"".'",--,

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FOREWORD.Theidea of the construction of a canal across theIsthmushasbeen thedreamofall nations oftheworld ever since the day when Balboa first landed ontheIsthmusin 1500.Hehadhardlysetfoot on dry land beforehebegan the search for a natural waterway between the two continents. Failing to find anything of the kind,hehadone of his followers,anengineernamedSaavedra, prepare plansandsurveysofanartificial water way, but,afterstudying the subject for a period of more than ten years,hereported on the projectas being impracticable. For over two centuries following this the project dropped from sightandit was not until the early part of the nineteenth century thatthe'matterwas again taken up.In1814 Spain again under took the consideration of a canal, but without any result. Following this both England and France became interestedandmademany studiesandsurveys of various routes..In1835 the UnitedStatesjoined the list of those interested in the construction of a canal and had studiesmadeof several of the feasible routes.Itis interesting in this connection to Imow that, even before this time, Goethehadprophesied that the UnitedStateswould eventually have to build the canal.[5]

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In1838 France secured a concession to build a canal,butallowed it to lapse through failure to do any work.In1848 Messrs. Aspinwall, Chauncey and Stephens secured a concession from the Governmentof New Granada for the constructionofa railroad across theIsthmus,which work they carried to a successful conclusion in 1855. For a while this road filled the demand for a trans continental highway, but in 1870 the United States again became interested andenteredintoanagreementwith Colombia for the construction of a canal; nothing was done, however, and in 1876 a Frenchman, LieutenantL.N.B.Wyse, secured a concession to build a canal and it was his concessionthatwas later transferred to the Universal Interoceanic Canal Company. This company began active construction work in 1881,butfailed in 1888 and, although a new company was organized in 189{ it continued operations on a small scale, doing simply enough to maintain its franchise, until 1904, when it sold out to the United States. On April 23, 1904, the stockholders of the NewPanamaCanal Company formally authorized the saleofthe company's propertytothe United States upon paymenttothe company of thesumof $40,000,000.Thetransfer of the property on theIsthmuswas made May 4, 1904, the United States being represented by LieutenantMarkBrooke, Corps of Engineers,U.S. Army.[6]

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,THEPANAMACANAL.

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CULEnRACUT.LOOJi:INGNORTHFROMTHEDIVIDE.

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THEPANAMACANAL.,THECANAL ZONE.HECanal Zone is a strip oflandtenmiles wide, five mileseachside ofthecenterline oftheCanal, extending from the At lantic tothePacific.Alltold, it contains 436squaremiles, of whichtheUnitedStatesnow ownsabout363squaremiles.Theremainderis privately ownedandwasnotacquired by the Government,asit wasnotneededforthecon struction of the Canal. If, however, thislandshould everbeneeded,theUnitedStatescan by itstreatyright acquire,eitherby purchase or by the exercise of the right ofeminentdomain, any lands, buildings,waterrights, orotherpropertiesnecessaryfor the construction, maintenance, operation, sanitation, or protection of the Canal.Thetwo cities ofPanamaandColon, although within the boundaries of the Canal Zone,areex cluded fromitandareundertheGovernmentofPanama.Theyhave no outlet, however, except throughtheZone.TheUnitedStatesreservesthe right to enforcesanitaryordinances in those two cities,andalso to maintain publicorderintheeventthatthe Republic ofPanamaisunableto do so.[9]

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ROUTEOFCANAL.TheCanal traverses this Zone from Colon toPanamain a general southeasterly direction,Panamabeing located 22 mileseastof a line runningduesouth from Colon.Inpassing through the Canal fromtheAtlantic vesselsentera sea-level channel extending from deep waterintheAtlantic tothefoot ofthelocksatGatun. This channel is 7 miles in length, 500 feet wideand41feet deep. At Gatun, vesselsarelifted from sea-level to85feet above through a flight ofthreelocks, passing directly into the watersofGatunLake. Gatun Lake isanartificial body of water withanareaof approximately 164squaremiles. This lake is formed by impounding the waters oftheRiver Chagresandits tributaries bymeansof a largedamatGatun, wherethereis abreakin the range of hills which surround the basin of the Chagres.Bybuilding adama mileandahalflong across this gap,itis possible to back up the waters oftheChagresandform theGatunLake.Thesurface of this lakestands85 feet above sea level, thesummitlevel oftheCanal, and extends fromGatun.clear throughtheCulebra Cut to thesouthernendatPedroMiguel, a distanceof32 miles. From the foregoing, it canbeclearlyseenthattheCulebra Cut is merely a spur of theGatunLake,thesamewater level existing in the Cutasinthebalance ofthelal{e.[10]

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Vessels after entering the lake maygoatpractically full speed for a distance of23miles from Gatun to the mouth of the Cut. The first16miles of the channel through the lake istobe1,000 feet wide and is marked by buoys on the surface of the lake, then for four miles the chan nel is tobe800 feet wide, narrowingto500 feet for three miles before entering the Cut. Through the Culebra Cut, which is 9 miles in length, the channel is to be 300 feet in widthatthe bottom. Passing through this Cutata re duced speed vessels arriveatthe Pedro Miguel Lockatthe south end, through which they are lowered in one step from85feet above sea-level to55feet above, a drop of30feet, passing out into Miraflores Lake, a small artificial lake coveringanareaof about two square miles. This lake is formed by impounding the waters of the Cocoli, the Rio Grande and the Pedro Miguel Rivers by meaus of the dam, locks and spillwayatMira flores.Thedamatthis point runs practically parallel to the locks on their west side instead ofatright anglestothem. This is done in ordertotake in theCocoli River, which comes in from the west, striking midway of the locks, which makes it necessary eithertodivert this stream or elsetobuild a dam soasto throw it back into the lake. The latter plan gives additional water for the lake and avoids the silting up of the sea level portion of the Canalatthe pointatwhich the diverted Cocoli would enterit.The spillway is[11]

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located on the east side of the locks between the side wall and a rocky point, and is of sufficient size to discharge all the water that might flow through one of the twin locksatPedro Miguel in the event that an accident should establish free conulllmication between Gatun and Mira flores Lakes.Inthis way, an accidentatPedro Miguel does not necessarily endanger the locksatMiraflores. Passing through the Miraflores Lake a dis tance of a mile and a half through a channel500feet in width the vessels arriveatthe Miraflores Locks and pass down through two locks in flight from55feet above sea-level to the sea-level channel on the Pacific side, steaming out through this channel from the foot of the locksatMiraflorestodeep water in the Pacific, a distance of 8 miles.Thetotal length of the Canal is 5072 miles and the time for passing through from one ocean to the otherwiIIbe from ten to twelve hours, ac cording to the speed a vessel maintains in the lake area.Threehours of this timearetaken up in passing through the six locks.Ofthe total length of the Canal,40mileswiIIbe of sufficient width to allow vessels togoatpractically full speed, there being15miles of sea-level chamlel, 7 on one side and 8 on the other, and 25 miles of open lake navigation in the two lakes, in all of which the minimum channel width is to be500feet, and the maximum 1,000 feet. This leaves[12]

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only 1072 miles which isatall narrow, 9 miles being in the Cut where the bottom width is tobe300 feetandthrough which vessels will goata reducedrateof speed,andtheremainder being through the locks, where the vessel willbetowed bymeansofelectric towing engines. Everywhere,except throughthelocks vessels willgoundertheir own power.OCEAN LEVELS.Thegeneral conceptionseemstobethatthePacific Ocean is higher thantheAtlantic; this, however, is not the case.Meansea-level,thepoint midway between extreme high and low tide, is exactly thesamein both the AtlanticandthePacific.Thedifference is all in the tides.Thereisanaverage tide on the Pacific of 20 feet, whilethereareapproximatelybut20 inchesoftide ontheAtlantic side. This excessively high tide on the Pacific side is apparently duetothe shapeofthe Bay ofPanama,which, being shaped like a funnel,tendsto exag gerate the actionofthe tide.Thesamething occursatseveral otherpointsthroughouttheworld, the most remarkable case beingtheBay of Fundy inNova Scotia, wherethetide sometimes rises and falls60feet.[13]

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FLATARCHINTHECHURCHOFSANDOMINGO,PANAMA.ThisarchstandsintheruinoftheOldSanChurchwhichwasdestroyedb)'firein175G.Itspans50feet,is35feethighatthecrownand3:1fectat,thespring.ThequestionastowhetherPauamaissubjecttosevereearthquakesisfrcquentlyasl
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BREAKWATERS.Breakwatersarebeing constructed on both the Pacific and the Atlantic sides.Theone on the Pacific end is simply an extension of a large dumpatEastBalboa of material excavated from the Culebra Cut, connecting Naos Island with the mainlandanddesigned to cut off a cross-current which comes inatright angles to the line of the Canal. This current although moving slowly carriesanenormous amount of siltandsand, and it was to prevent the filling in of the sea-level portion of the Canal that this breakwater was constructed.TheToro Point breakwater on the Atlantic side extendsnortheastfrom Toro Point a distance of 11,000 feet and is designedtoprotect the BayofLimon from heavy storms which occur during the winter months andarecommonly knownasNorthers.Thesestormsareof such violence that when one occurs vessels cannot lieatthe docksatCristobal and Colon,butareforced to move out into deep watertoseekshelter farther down the coast in the land-locked harbor of Porto Bello.Inadditiontothisbreakwatera mole is being built in connection with the dock improve ment workatCristobal, behind which the docks willbeconstructed.Ifit shouldbefound after this mole is completed that still further protection is required then a second breakwater willbeex tended from the headland opposite Toro Point.1151

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OJ,OFRE:"iCHLOCOMOTlY.ES,NEAREMPIRE,ZONE.

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FRENCHWORK.Active work wasstartedbytheFrenchon their Canal in 1881,andthis first French Company, which was organized byDeLesseps, failed duringthelatterpartof 1888 after spending $260,000,000.00.,For five years the company remained inthehandsofa receiver,andin 1894theNewFrenchCom pany was organizedandkeptupthework on a very small scale until 1904 whentheUnitedStatestook overtheconstruction.Theplanofthis lastFrenchCompany was to build a lock type canal with a totalofeight locksandasummitlevel through the Culebra Cutat97 feet above sea-level. Startingjustbehind Cristobal Point, inordertosecuretheprotection ofthatpoint againsttheNorthers, and extending for16miles inland to Bohio,theCanal was tobea sea-level type. At Bohio adamandtwo locks were tobelocated, formingtheBohioLakewith a surface levelof65feet above sea-level. Passing through this lake a distanceof14 milesthevessels would arriveatBasObispoatthenorthernendoftheCut, whereitwas intended to locate two more locks with a combined lift of32feet.Inorderto secure water forthesummit level throughtheCut it would havebeennecessary to buildanadditional reservoiratAlhajuela farther upthevalleyoftheChagres, bringing a ditch line alongthehillsides from thislakedownandintotheCut. Passing through[17]

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ABANDONEDFRENCHLADDERDREDGES.

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theCut, vessels were tobelowered tothePacific through four locks, oneatParaiso, twoatPedroMiguel,andoneatMiraflores, from which point a sea-level canal 8 miles long ledoutinto deepwaterinthePacific.FRENCHPURCHASE.TherightsandpropertyofthisFrenchCompany werepurchasedbytheUnitedStatesfor $40,000, 000.00;andup todateour countryhasrealized on this purchase,ona very conservative estimate, over forty-two million dollars.Outof80,000,000 cubicyardsofexcavation work whichtheFrenchCompanyhaddoneonly 30,000,000yardswere useful intheconstructionofthepresenttypeofCanal,andinestimatingthevalueoftheFrenchpurchaseanallowanceof$25,389,240.00 wasmadefor this excavation work.Ithadcost approximatelyonehundredandtwenty million dollars.ThevalueofthePanamaRailroad was estimatedat$9,000,000.00. This railroad was ac quired bytheFrenchata costof$18,000,000.00.Inaddition tothesetwo mainitemsthepurchaseincluded agreatdealofmachinery,andtheCommission is today using 85Frenchloco motivesand7ladderdredgesincluded intheproperty purchased.TheFrenchalsoturnedover agreatmanybuildings, maps,andscientific data, including recordsoftheflowoftheChagres[19]

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.IRiver through a period of15years.Ontheserecordsitis impossible to place any cash value, as they would not have been availableatany price,hadnot the French kept these records, and with the present type of canal it is a matter of vital importance to be able to estimate ac curately the volume of the flow of the Chagres,asit istheChagresthatsupplies the water tofillthe Gatun Lake and make the loclmges through the Canal. Now, due to the factthatwe have secured these French records, we have a com plete record of theflowof the Chagres extending through a period of twenty-three years.RELOCATIONOFPANAMA RAILROAD.Astheconstruction of the Canal progressed it became necessary from time to timetoaban don small sections of the originalPanamaRail road line, which was built in 1850 by three Americans, Aspinwall, Stephens,andChalUlcey.In1908, the section between Mindi and Tiger Hill was relocated as the old line passed right throughthesite oftheGatlUl Dam and Locks.In1910, the section between Pedro Miguel and Corozal was relocated, establishing the line per manentlyatan elevation sufficiently high to be above the level of Miraflores Lake, and on Feb ruary 15, 1912, the relocated line between Gatun and Matachin was put into service, as the rising[201

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water of the Gatun Lakedueto the closingupof the ChagresatGatun on February9,soon flooded most of the old line between these points.TheGattm Lake nowstands50feet above sea level,atwhich elevationitfloods the old railroad rightofway to about Tabernilla and covers anareaof over90sqllare miles. Finally, with the Canal completed, a new rail road will have been constructed, running from Colon toPanamaentirely on theeastside of the Canal.Thenew road after leaving Gatun swingseastalong the hillsides,andcrossing through the lake on highearthfills, follows the borders of the lake to Gamboa, where it crosses the Chagresona steel girder bridge a quarter of a mile long. Fromhereit swings away from the Cut and, IJassing around back of Gold Hill, follows thePedroMiguel valley to Pedro Miguel. Originally it was intended to carry the railroad through the Cut on a bench10feet above the water,butthe slides in the Cut made that impracticable.GATUNDAMANDLAKETheGatunDamis a huge earth structure and is, in fact, more of a mountain than a dam.Itis so constructed as to complete the natural range of mountains which, exceptingatthis one point, entirely surround the low-lying basin oftheChagres. By completing this basin, it is possibletoretain the watersofthe Chagres and thereby form the Gatun Lake.[21]

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OLD,1FRENCHEXCAVATIONINCUTNEAREMPIRE.

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Thedam is constructed of two outer walls of dryfill,a large part of which was excavated fromtheCulebra Cut.Thesetwo walls, or toes, as theyareusually called; were constructed soasto be 1,200 feet apart (inside measurement) and this space in between the two walls was filled with a mixture ofsandand clay which was suckedupfrom the river bed of the Chagres, both above and below the dam, by means of large suction dredges and then pumped through long pipe lines into the space between the two walls of dry earthfill.About20per cent of the material passing through these pipe lines was solid matter, the bal ance water. After the solid matter settled the sur plus water was drained offandin that way the inner portion of the dam was built up. This inner core is usually known as the hydraulic core and forms the watertight portion of the dam. After the hydraulic corehadbeen carried a short way above the water levelitwas discontinued and the outer walls were then carried higherandcloser together until they entirely encasedandcapped over the inner core.TheGatunDamatthebaseis 2,100 feet, or about a half mile thick,400feet thickatthe water surface, and100feet wide across the crest.Thecrest of the damstands105 feet above sea-level and20feet above the surface of the water of the lake.Thelength of the dam measured along the crest is 7,500 feet, but of this length only 500 feetwiIIbe subject to the full pressure of85feet[23]

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of water, due tothenatural rise of the ground along the inner slopes of the dam.Inconnection with this dam it is interesting to knowthata Frenchman named Lepinay was the first to propose the plan of constructing a damatGatun.Heproposed this plan in 1879 totheInternational Scientific Congress whichhadbeen convenedatParis to determine upon the general route of the proposed canal, butDeLes seps, who was the leading spirit of this Congress, was so strong an advocate of the sea-level canalthatLepinay's plan was hardly discussed, and is simply a matter of record.SPILLWAY.Thespillway, which is located about midway of the dam, is built right into a natural hill, which stoodatan elevation of 110 feet above sea-level. This hill was practically solid rock, soitwas only necessary to cut a channel300feet wide through this hill and line it with concrete, building a dam acrossthehead of this channel to form the spill way or regulating works for Gatun Lake. This dam forms nearly a semicircle across the head of the spillway channel and will be constructed of solid concrete up to elevation69.Atthis level piers rise45feet apart on the crest ofthesolid portion ofthedam, and in between these piers come the steel gates nineteen feet high which controlthelevel of the lake.[24]-

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Withthesegates closed,thecrest of thedamwouldbe88feet above sea-level, sothatit wouldbepossible to store up waterintheGatunLakeup toabout87 feet above sea-level.Thenormal level of the lake is tobe85 feetandit willbemaintainedatthatlevelduring most of theyear;justatthelast of the rainy season, however,thelake level willbebrought up to 87 in order to supplythewater for lockages duringthedry season. This will giveanadditional two feetofwater overanareaof164 square miles, which wouldbesufficient tomake58lockages a day duringthedryseason;thatis, ten more than could possiblybemadewith vessels following one anotheratintervalsofonehour. With the lakeat85the spillway willbecapable of discharging 154,000 cubic feet per second, which is more than thegreatestmomentary discharge on the Chagres RiveratGatun. .IftheGatunLake should evergoto elevation92thespillway wouldbecapable of discharging over 200,000 cubic feet of water per second, which is very nearly equal to the discharge of the Horse shoe FallsatNiagara.Inadditiontothe controloftheChagres effected by meansofthe spillway,thereis thegreatreservoiring effectofthe Gatun Lake, it beingofsuchgreatareathatit would take thegreatestknown flood of the Chagres River nine hours to raise the levelofthe lakeonefoot, even though no water was discharging through the spillwayatGatun.[25J

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WATERSUPPLY.Tothosewhoareskepticalastothesupplyofwaterwhich willbeavailable to filltheGatLIllLakethefollowing figuresmaybeofinterest.TherainyseasonontheIsthmususuallyextendsthroughthelasteightmonthsoftheyearandtheremainingfourmonthsmakeupthedryseason.At Colontheaverageannualrainfallamountsto 130inchesayearand,asonecomesacrosstheIsthmusfrom Colon toPanama,therainfalldecreasesgraduallyuntilatPanamatherain-fallaverages70inchesperannum.Now,asonegoeseastandwestfromtheZone,onegetsintosectionsthataremoremountainousinwhichitrainsalmosteverydayintheyear, sothatatPortoBelloonefindsanannualaveragerain fall of 173 inches.In1909PortoBellohad237inchesofrain;duringonemonthofthatyearithad58inches,ormorethantheaverageannualrainfallaroundNewYorkorBoston, which is40-45inches.PortoBello also holdstherecord for 24hours'rainfall, whichamountedto 10.86inches.Thegreatestrecordedrainfall foronehouris 5.86inchesatBalboainJLUIe,1906.TheheaviestrainfallofshortdurationoccurredatPortoBello inDecember,1911,amountingto2.46inchesinthreeminutes.TheareadrainedbytheChagresanditstributariesis1,320squaremiles,andin 1910thevolume[26J

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of the discharge ofthatriveratGatunequaled onceandahalfthevolume of waterthatwillbecontained intheGatunLake. At Gamboa,theriverhasbeenknown to rise40feetin24 hoursandto discharge 100 timesthewaterthatitdoes in the dry season, amounting during one flood to a flow of 170,000 cubicfeetper second, which equals two-thirds of the volume of water which passes overtheHorseshoeFallsatNiagara.POWERPLANTS.Ontheeastside of the spillway will be located a large hydro-electric plant. This plant willtakewater fromtheGatunLake,passitthrough tur binesanddischargeitthrough openings in thesidewall of the spillway channel,therebygenerat ing all the power necessary to operatethelock machinery throughout theentirelength oftheCanal. This plant consists ofthree2,000 kilowatt generators, one of which is a reserve, producing ordinarily over 5,000 horse power with areserveof 2,500horsepower.Thefall from the level ofGatunLake tothelevel ofthespillway floor being75feet,thesupply of water for operating this plant will be ampleatalltimesoftheyear. Asanextra precaution, however, thepresent6,000horsepower construction plantatMiraflores, which isanoil-burningsteamplant, will be re tainedasanauxiliary to theGatunplant shoulditeverbeneeded.[27]

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STEAMSHOVELLOADINGROCI\:FORTHETOROPOINTBREAI\:WATER.

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CULEBRACUT.TheCulebra Cut, from which it was necessary to excavate over105,000,000cubic yards of rock and earth, representing nearly half of the excava tion work on the entire Canal, beginsatthe point where the Canal leaves the valley of the Chagres near Bas Obispo and follows the winding valley oftheRio Obispo until it reachestheContinental Divide near Culebra. After cutting through the divide it follows the valley of the Rio GrandetoPedro Miguel.TheCut is nine miles long and willbe300feet wide on the bottom.Atall the angles it is widened out sufficiently to allow a vessel1,000feet long to maketheturn with perfect ease.Theaverage depth to which it was necessary to excavate below the natural surface was approximately120feet through the entire length of the Cut.Atthepoint where the Continental Divide was severed between Gold Hill and Contractor's Hill the cutting will average375feet.EXCAVATION.OnJanuary1,1913,there remained to be exca vated throughout the Cut5,501,419cubic yards of material.Inthe year1911, 16,600,000cubic yards were excavated, so thatatthis time there remains to be tal{en out less material than was excavated in the past twelve months.The5,501,419cubic yards which are stilltobeexcavated lie in thel29]

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Cut in the shape of a mOlmt 4 miles longatthebaseand25feet high. At the highest point, this summit is locatedjustopposite Culebra, and the mound slopes both ways from that level, so that on either end of the Cut a point is reached where the excavation workhasbeen carried downtothe final grade. Thirty-eightsteamshovels areatwork excavating this material, each one taking out on an average 1,500 cubic yards of rock and earth each day. Records have been made, however, of over 4,000 cubic yards in eight hours.Asa matter of fact, thenumberof hours that asteamshovel is generally employed in loading cars amounts to only about six,asthe problem in the Cut is more one of transportation than of excavation, and it is not possibletokeep trains standing under the shovels more than six hours out of the eight.Alltold, therearenow about75miles of track in the Cut, of whichitis necessarytomove about a mile each day.Atthe present time, about 150 loaded trains ofeartharepassingoutof the Cut daily, butatthe time when the excavation work wasatits maximum 175 trains were leaving each day, which amountedtoabout one train every two and one-half minutes.Themonthly output from the Cut reaches closeto1,500,000 cubic yards.Thebuckets used on most of the shovels in the Cut load 4 and 5 cubic yardsata time, which by weight means from 6totonstothe bucketful.[30J

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DRILLINGANDBLASTING.Allof the material which is excavated by the shovels is first drilled and then blasted before it can be handled, and in the length of the Cut a great number of drillsareconstantly working.,Allof these drills, of which therearetwostyles, churn and tripod, are operated by compressed air supplied from one long air main which par allels the line of the Cut. Three compressor plantsarepumping into this line, one located near the middle and oneneareach end of the line.Theaverage depth to which the holes are drilled is24feet, and after drilling to this depth a small charge of dynamite is placed in the hole and discharged by means of the magneto battery, enlarging in that way the sizeof the holeatthe bottom. Then, after the hole has cooled off it is readytoreceive the large charge of dynamite varying from75to200 poundstoeach hole. This charge is exploded by means of the regular electric light current, the ordinary magneto bat tery having been found too unreliable and its use resulted in too many misfired shots, which hadtobe subsequently excavated; thereby greatly endangering the lives of the workmen. Each month an average of75miles of drill holesaresunk, and if all the drill holes which have been put down since the United States has beenatwork were placed end to end the hole would pass entirely through the earth, coming[31]

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SHOVELINCULEBRACUT,nURlEDUNDERSMALLROC!\:SLIDE,:MAY31,1912.

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out in the Indian Ocean south of the Island of Sumatra. Five hundred thousand pounds of dynamite are used each month in the Cut, and on the entire Canal 800,000 pounds are consumed.SLIDES.Atthe present time, there are in the length oftheCut nineteen slides varying greatly in size, the totalareainvolved amounting to 210 acres. One of the largest is the Cucaracha slidejustsouth of Gold HilI, which started duringtheFrench time and now coversanarea of 47 acres, and is broken back a distance of 1,800 feet from the center line of the Cut. A great number of smaller slides have occurred throughout the Cut, the worst section for slides being right around the town of Culebra. From time to time small slides have occurred here on both theeastand west banks, which have gradually combined, forming two large slides, until they have become more difficulttohandle than the Cucaracha slide. Two general characters of slidesarefound in the Cut. One is the true slide, which is a mass of earth that is sliding from a hard surface that pitches towards the Cut and this slide is glacial in its action. There are no means of overcoming or correcting this character of slide; the only thingthatcan be done is to take the material outasit slides in and continue todoso until the sliding material reaches an angle flat enough to stand.Theother[33]

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SLIDEOF300,000CUBICYARDSINTHEEASTBANKOFCULEBRACUT,AUGUST21,1912.

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is a slide that is caused by the great weight of the banks on either side of the Cut weighting downandsqueezing out the soft underlying strata, which in giving away bulge upatthe bottom of the Cut, allowing the banks on either side to settle.Thesebanks in settling break loose and begintomove toward the Cut. The first movementof thebanksin this kind of slide is down ward and then the lateral motion follows.TheslidesnearCulebraareof this type.Inordertocorrect this character of slide steam shovelsareworking on top of the banks, taking material off the top, thereby reducing the weight of thebanksand to a certain extent preventing further sliding.DIVERSIONCHANNELS.Asthe Cut follows the valleys of the Rio ObispoandRio Grande, it was necessary to divert thesestreamsandtheir main tributariestoprevent the Cut from being flooded during the rainy season. Sothatparallelingtheline of the Cut on the west side we have the Rio Grande and Comacho diver sions, and on theeastside the Obispo diversion.Thesediversion channels parallel the line of the Cutandcarry off the water of these small streamsaswellasa large part of the surface drainage water, thus preventing the flooding of the Cut itself.Thesechannels were allstartedby the French,butwere enlarged after the UnitedStatesbegan work on the Canal.[35]

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GATUNLOCI\:SINCOURSEOFCONSTRUCTIO:-l.

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LOCKS.Therearesix locks in the Canal, three in flightatGatlm, oneatPedroMiguelandtwo in flightatMiraflores.Alllocks are constructed in pairs, so that vessels callgoin opposite directionsatthesametime. Each Jock or flight of locks is in generaltobe reserved for ships going in one direction, the twin lock or flight being used for vessels going in the opposite direction.Thelength of the lock chamber is 1,000 feet, the width 110 feet, and the depth of water over the sills4173feet in fresh water and4Dfeetinsalt water.ThePedro Miguel Lock is thesamein all the essential features as the other locks and as there is only one liftatthis point it is thebestone to describe. A simple definition of a lock is a walled chamber between two bodies of water of different levels having gatesateither end, in which it is possibletoconfine vessels while they are being raised or lowered from one leveltoanother by allowing water to flow in or out of the lock chamber.Themethod of raising or lowering the level of the water in the lock chamber varies on different lock canals.Thelock chambers on most of the old canalsareemptied or filled through sluice gatesthatslide upanddown in the lock gates themselves. This system, however, caused agreatdeal of surging of the wateratthat end of[371

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the lockatwhich it was flowing in or out, and the systemthathas been adopted on thePanamaCanal was designed with the idea of avoiding this disturbance of the water in thelockAllthe locks on thePanamaCanal have two parallel lock chambers separated by a center wall. The water is brought in or out of these chambers through huge tunnels18feet in diameter passing lengthwise of the lock through the center and side walls. Branching out from these tunnelsatright angles and running outunderthe lock floorarelateralsandthese laterals communicate with the lock chamber through openings in the lock floor.Theflowof water in or out of the lock is controlled by the gate valves locatedatboth the upperandlower ends of the feed tunnels.Inordertoraise the water in the lock chamber the valvesatthe lower endareclosedandthe onesatthe upper end opened. The water then flows from the upper level into the lock, passing down,the tunnel in the side wallandout through the lateralsunderthe floor, coming up through the openingsinthe floor.Itcontinues to flow in this way until the elevation of the water in the lock chamber is thesameas that of the water above. To lower the water in the lock the pro cess is simply reversed.Theupper valvesareclosed and the lower ones opened. The water then flows out from the lock chamberandpassing back through the same tunnelsthatbrought it in seeks the level of the water below. So that. in[38]

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orderto raise a vessel from one leveltoanother,thelevel ofthewater inthelock chamber is brought to thesamelevelasthatatwhich the vessel stands.Thelock gatesarethen opened,thevessel passes intothechamberandthegatesareclosed.Wateris then allowed to flow into the lock until the vessel is raised to the level of the upper body of water,andwiththesamelevel on both sides oftheupper gates those gatesarethrown open,thevessel passing outata greater elevation thanthatatwhichitenteredthe lock.Thebig tunnels passing through the side wallsarethemain operating tunnels, the one throughthecenter wall beinganauxiliaryusedtoassistin fillingthelock during the latter part of the opera tion, thereby increasing the volume oftheinflowatthetime whenthevelocity ofthewater enteringthelock fromtheside wall tunnels is decreasing, keeping up inthatwayanaverage rate of filling which wouldamountto about 2 feet per minute'. So that,atPedroMiguel, where the lift is30feet, a vessel wouldberaised from one level totheotherin15minutes.Thedesiredrateof filling can bekeptup forthe600-footand400-foot locks bytheside culvert only.Itis probablethatthecenter walltIlinelwillbeusedonly in case ofthelOOO-footlockages. Fromthecenter wall tunnel laterals, which alternatewith laterals fromtheside walls, lead outunderthefloors of both lock chambers. Theyarecontrolled, independent ofthemain tunnel,[39]

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CROSS-SECTIONOFLOC:KCllAMIlERANDWALLS,GATUNLOCHS.A.CIIIvertjncentel'wall.U.COllllecUonsbetweencenterandlateralculvert.C. Later'aleulvcl'LD."Veilsopeningt'l'frrnlateralculvc)tsintolockchanlhcr.E.Culvertinsidewall.Ii'.J)rainagcgallery.G.Galleryforeleetl"iewires.H.Passagewa.yforoperators.

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by cylindrical valves locatedatthe head of each tunnel, sothatit is possible to close the laterals all the way down on one side, opening those on the other side,andfeed water to one lock chamber; or, by reversingtheprocess, feed water to the other chamber. By opening the valves to the laterals on both sidesiUspossible to pass water through from one chamber to the other, inthatway effecting a saving of water whenever vesselsaregoing in opposite directionsatthesametime. Another means of economizing water is by using the intermediate lock gate which divides thelOOO-footlock into two sections of600and400feet, respectively; sothatin putting through small vessels it is not necessary tofillor empty the entire chamber.ELECTRICLOCOMOTIVES.Theprotective devicesareone of the most interesting features of the lock construction, and ofthesethe electric locomotivesarethe most important. About ninety per cent of all accidents to other locks have been due to misunderstanding in signals between the captain and engineer of the vessel, and all accidents of that kindwiIIbe eliminated by requiring vessels togothrough the locks in tow of electric locomotives operating on the centerandside walls of the locks. A vessel comes inandtiesupto the center wall, which is extended beyond the side wallsatboth the[ 41]

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ENTRANCETOUPPERGATUNLOCI(FROMTHEL.Uill.

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upper and lower ends of the lock simply to actasa wharf or mooring wall.Thevessel waits here untilthelocomotives come down and tow it up to a point where the locomotives on the side walls make fast their lines. The vessel then goes into the lock chamber with two locomotives in front towing, one on eitherand two others behind to retard whenshegets into proper position.Thesetowing locomotives operate on tracks close to the edge of the wall and engage in a centercograil. While running on thiscograil the maximum speedatwhich they can operate will be two miles per hour. When they have completed a tow, however, they switch overtoa track farther back fromtheedge of the wall andherethecograil is omitted, sothatthey can returnata greater speed.PROTECTIVECHAIN.Should a vessel not obey the order to stop out alongside the center wallbutcome ahead, it first would encounter a chain stretched across the entrance to the lock chamber. This chain connects on either side with large hydraulic cylinders located in shafts in the lock walls. The pressure from these cylinders causes the chainasit plays out to offer more and more resistance tothemotion of the vessel.Thechain is capable of stopping in70feet a 10,000-ton vessel running four miles per hour. The stock from which it istobe forged is three inches in diameter.[431

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,III,"GENERALvmwOFTHEPEDROMlGUELLOCI\:

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When not inusethecylindersareforced up and the weight of the chain carries it down into the groove inthebottom of the lock floor and the vessel passes over it.GUARD GATES.,Ifa vessel should break through the fenderchain, it would then ram the lock gate,butwiththis contingency in view two gates instead of one have been providedatthe upper and lower ends of the highest lock in each flight, the upper or guard gate of each pair serving to protect the lower gate from ramming. Both gates would have to be broken down to put the lock out of commis-SlOn.LOWER GUARD GATE.Atthe lower end of all thesetsof locks a small guard gatehasbeen put in, mitering the other way from the main lock gates, which miterto-'wards the high level, and it has been designed to serve two purposes: first, as a coffer gate or dam, ifatany time it is necessary to pump the water from the lower lock chamber: second,asa guard gate to the lower lock gate, for, miter ing as it does, it will stand a heavier blow from the lower side than the lock gate itself.EMERGENCYDAM.Ifall of these devices should fail and there should beanaccident which would establish[45]

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free communication between the two levels aboveandbelow a lock, a most destructive accident wouldbethe result, for the velocity of the water flowing through the lock chamber would be 24 feet per second and the discharge would amount to 90,000 cubic feet per second.Inorder toshutoff this waterandprevent it from tearingoutthe lock floor it is necessary to employ a device knownasanenergency dam, of which therearetwo installedatthe upper end of eachsetof locks, one for either side.Theseresemble a swing bridgeandwhen put intousetheyareswung out across the lock and from their lower side asetof open-work wicketsarelowered, engaging in a grooved sill onthelock floor.Whenthese wicketsaredownandin place, small plates resembling little flat carsareallowed torundown, one on each wicket, building up a row of plates across the bottom, one joining the other.Whenthe first completesethasbeen let downninefeet of the water will beshutoff, and then an othersetof plates willbelet down, until finally the water rushing through the lock willbeentirelyshutoff.Ofcourse, there willbesome seepage through the plates, but the water above this tem porary dam will be still water and the electric locomotives willgodown andtakein tow a floating caisson, or hollow steel float, and towingitaroundseatit against a sillatthe upper end of the lock chamber.Thenby filling water into the caisson it is sunk, entirely shutting off the water flowing[46J

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throughthelock.Theemergencydamisthenraisedandthenecessaryrepairsmadetothelocks.LOCKGATES.Theconstructionofthelockgatesis also inter esting.Theywere built up of big horizontal girders weighing from 12 to18tons each, with vertical frameworkinbetweenandsheathing plate both on the insideandoutsideofthis frame.Theyarecellular in constructionandthelower half ofthegateisanairchamberwhich supportsaboutthree-quartersoftheweight of the gatewhensubmerged.Theupperhalfof the gate isarrangedwith openingsinthe plates ontheupstreamsidesothatwatercan flowinoroutoftheupper half ofthegateatthesametimethatitflowsinandout ofthelock, increasingtheweight of the gateasthe height ofthewater on the outside increases, overcoming inthatwaythelifting effect of the airchamberinthe bottom ofthegateasitis placeddeeperanddeeperunderwater.Thesegatesvary in height from 47 to 82 feet,andinweight from 300 to 700 tons toeachhalf gate.Ifeach halfgatewere laid flat one on top of theotherthey would build up a tower contain ing 58,000 tons of steel standing 32 feet higher thantheSinger Building in New YorlcThereare92halfgatesandeach is seven feet in thickness Another interesting comparative figure isonepertaining to the excavated material.Allof the[47]

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SANITAltYDIUI'nAltREL.Placedattheheadwate..sofast..eam,theseba....elsautomaticallyfeedcrudeoil,whichspreadsoutove..thesu..faceofthewater.

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excavated material which will have been taken out when the Canal is completed, including the 30,000,000 cubic yards of useful French excava tion, if loaded on one train of flat cars similar tothewooden cars one sees commonly on the work, would make a train over 110,000 miles long, reaching more than four times around the earth.SANITATION.No one single factor has been more important in making the construction of thisCanal a pos sibility thanthatof sanitation. One oftheworst snagsthattheFrenchranagainst was this very question of sanitation. Unfortunately, there are no accurate figures obtainable onthelives lost during the French time; the only figure available is for the mortality in Ancon Hospital, which for the eight years between1881and1888 amountedto5,527. But the French were,atthis'time, doing their work by contract and each con tractor was charged a dollar per day for each manhehadin hospital.Itwill readilybeunder stood, therefore,thatif the French contractor were anything liketheordinary contractor,nota very large proportion of the sick would go to this hospital.Wehearof many individual instances of heavy loss.Thefirst French director,Mr.Dingler, came to the Isthmus with his wife and three children.Attheendof the first six months all had died of yellow fever except him-[491

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self.OneoftheFrenchengineers, who was still ontheIsthmuswhen we first arrived,statedthathecame over with a party ofseventeenyoung Frenchmen.Ina month theyhadall died of yellow fever except himself.Thesuperintendentoftherailroad brought to theIsthmushisthreesisters;within a month theyhadall died of yellow fever.TheMotherSuperior of thesistersnursing in Ancon Hospital toldmethatshehadcome out with twenty-four sisters. Within a few years twenty-onehaddied, themostof yellow fever.Manyother instances of this kind could be cited. During the eight yearsthattheAmericans havebeenatwork on the Canal thedeathrol!hasreached 5,141, of which 995 havebeendeathsfrom violence. Forthefiscalyear1912thedeathrateper thousand ontheIsthmuswas lowerthanin almost any large city intheUnited States,asthefollowing figures will show:Deathsfrom accidents. ..........3.08Deathsfrom diseases 7.08 Totaldeathsfrom all causes 10.16Themost important workoftheSanitaryDepartmentandtheone whichhashadmosttodo with the reduction ofthedeathrateis undoubt edlythatwhichhasto do withthecontrol ofthebreeding of mosquitoes, so that I will speak only ofthatone feature of its work.[50]

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,Jhave found it a very prevalent idea among the visitors to the Isthmusthatthe mosquitoes have been entirely exterminated from the Zone; such, however, is not the case, for, although thereare448square miles within the Zone, the destruction of the mosquito is carried on over only about100square miles. Outsideo[this area of100square miles mosquitoes can be foundjustasthick as they ever were; but, by constant vigilance and effort, the number of mosquitoes in the sanitated areas has been reduced to such a very few that adult mosquitoes arebutseldom seen by the casual observer. For the purpose of sanitation, the Zone is divided into sanitary districts, each district being placed in chargeofa sanitary inspector.Asa general rule, the sanitary work is carried ontoa distance of about 1,000 yards outside the extreme limits of any inhabited district,asthishasbeen found to be about the flying radius of the varieties of mosquitoes which the Sanitary Departmenthasto deal with.Thework of controlling the mos quitoes within these districts falls under threeheads:FIRST:Elimination of favorable breeding places by filling, drainage, removal of grass to favor evaporation, clearing of banks of streams and other bodies of water to give access to fishthateatthe larvre of the mosquitoes, removal of vegetation and other foreign matter suchasalgre which gives shelter to the larvre of the[511

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mosquitoes, introduction ofsupplies to reduce thenumberof water-holding containers in which the yellow-fever mosquito breeds,andscreeningofsuch water containers as cannotbedone away with. SECOND: By oiling or larvaciding such bodies of water as cannotbeconveniently and economically eliminated, the oil llsed for this purpose being the ordinary crude oil and the larvacide a mixture of creosote, caustic soda andresm.THIRD:By preventing the access of mos quitoes to the inhabitants by effectively screening as many dwellings as possible and, in addition, by catching in specially designed trapsandbyhandsuch mosquitoesasfind their way into dwellings. By the constant application of these methods the malaria ratehasbeenreduced from about 6.83%ofemployees admitted each month to the hospital in 1906 to about1%per month for the current year,andin totally eliminating yellow fever fromthecities ofPanamaandColon and the Canal Zone, the last case of this disease having occurred in Colon in May, 1906.[52],

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INTERESTINGFACTS ANDFIGURES40 1,000 507210to123300 12 1,000110164 85to45 45LengthofCanal from deepwaterto deepwater(miles) Length from shore-line to shore-line (miles) .Timeoftransitthrough completed Canal (hours) .Timeof passage through locks (hours) Bottom width of channel, maximum (feet) Bottom width of channel, minimum, 9 miles Culebra Cut (feet) Locks,inpairs Locks,usablelength (feet) Locks, usable width (feet) .GatunLake,area(square miles) .GatunLake, channel depth (feet) Culebra Cut, channeldepth(feet) Excavation,estimatedtotal (cubic yards)212,504,138Excavation,amountaccomplished toJanuary1, 1913(cubic yards).....188,280,312Excavation by theFrench(cubic yards)78,146,960Excavation by French, useful topres-entCanal (cubicyards)...........29,908,000Excavation by French,estimatedvalue to Canal.$25,389,240Value of allFrenchproperty$42,799,826Concrete, totalestimatedfor Canal (cubic yards) ....................5,000,000[53]

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Weightofonecubic yardofconcrete orearth(pounds) ................. 3,000 RelocatedPanamaRailroad,estimatedcost. ...........................$9,000,000 RelocatedPanamaRailroad, length (miles)......................... 47.1 173 2.46 1.25 35,00075448 1,320 130 70MaximumgradeonPanamaRailroad (per cent) .Maximumcurve onPanamaRailroad (degrees) GageofPanamaRailroad (feet) Canal Zone,area(square miles) CanalandPanamaRailroad force actuallyatwork (about) CanalandPanamaRailroad force, Americans (about) ................ 5,000 CostofCanal,estimatedtotal $375,000,000 AmountspentbyFrench$260,000,000WorkbegunbyAmericansMay4,1904Dateofofficial openingJan.1, 1915 PopulationofColon. ............... 17,740-PopulationofPanamaCity. ........ 37,505TideonPacificside(feet) .......... 20Tideon Atlanticside(inches) ....... 26 AreadrainedbytheChagres River (square miles) Average rainfallatColon (inches) Average rainfallatPanama(inches) Average rainfallatPortoBello (inches) .Maximumrainfallofrecord for 3minutes(inches) .[541

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Maximumrainfall of record for 1hour(inches) .Maximumrainfallofrecord for 24hours(inches) .Maximumtemperatureofrecord(de-greesfahr.) .Minimumtemperatureof(de-greesfahr.) Averagemeantemperature.Meanrelativehumidity(per cent)..Evaporationperannum(inches).....MaximummomentarydischargeofChagresatGamboa(cubicfeetpersecond) Volumeofwaterpassing overtheHorseshoeFallsatNiagara(cubicfeetpersecond) Averageamountexcavatedin8hoursbyeachsteamshovelinCut(cubic yards) ......................... Record for 8hoursforsteamshovelsofanyclass (cubicyards).Recordfor 8hoursfor 70-ton shovels,3-yardbucket(cubic yards) Location ofRockCrushersandSandPits:AtlanticSide:RockQuarry,PortoBello, capa city, cubicyardsperday.....SandPits,NombredeDios. PacificSide:RockQuarry,Ancon Hill, capacity, cubicyardsperday.SandPits,PointChame.[55]5.86 10.86 96.6 59 79 8952170,000250,0001,500 5,554 3,910 3,000 2,000

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Amountofoilusedpermonth(barrels) Cost ofsame(per barrel) Amount of coalusedpermonth(tons) Cost ofsame,deliveredinfire-box (per ton) .......................Numberof milesoftrack onIsthmus(about) .Deathrateper thousand, 1912: Accidents .Disease....................... Total from allcauses.EQUIPMENT.SteamShovels: 105-ton, 5 cubic yard dippers. ..... 15 95ton, 4and5 cubic yard dippers. 32 70-ton,2;..-2and3 cubic yard dippers 35 66-ton,2;..-2cubicyarddippers. ....6 45-ton,cubicyarddippers. .... 1026ton...................1 Trenching shovel,cubicyarddipper. ......................1 75,000 $1.10 35,000 $6.00 500 3.08 7.08 10.16 Total. ....................... 100Cranes:American. .....................60French........................9 Total. .......................69[56]

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Locomotives: American 106tons.....................100105tons40117tons20 Total. ..................... 160,French.20tons5 28tons...................... 2030tons1638tons36,Decauville. ..................8Total. ..................... 85 Narrow gauge, American, 40 tons. .10Narrow gauge, American, 16tons.. 23 Electric. ....................... 12 Total. ....................... 45Grandtotal. ............... 290 Drills: Mechanical churn, or well. ......265 Tripod. ........................361 Total.[57]626

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Cars:Flat,usedwith unloading plows...1,800Steeldumps,large..............600Steeldumps,small1,200Ballastdumps,steel............. 12Ballastdumps,wood. ............ 12Steelflats. .....................500 Narrowgauge..................200Motor.........................6PayCar1Total.Spreaders.Trackshifters,...................Unloaders.Piledrivers. 4,331 26 9 26 13Dredges:Americanladder.Frenchladder. Dipper .Pipe-line.Sea-goingsuction.Clamshell .Total.Rockbreaker,floating .Tugs............................Towboat. .Houseboats.[58]1737212111212

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Clapets..........................11Piledriver,floating. ............... 1Craneboat.......................1Barges,lightersandscows.......... 70Launches........................ 14Cutters..........................3Drillboats, ......2Derrickbarges...................2PANAMARAILROAD.Locomotives:Road(12 oilburners)............ 36Switch........................ 34Total........................ 70Cars:Coaches.......................57Freight1,477Total. Locomotivecranes.Piledriver,track.Piledriver,floating .Tugs............................Lighters:Coal, allsteel. Cargo,steelandiron.Total.......................[5915 81,534 411213

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.J/GeneralMapofthe CanalZoneandthePanamaCanal, printedinthree colorsandboundinboard covers, hasjustbeen issued.Sizex13inches, folded.PublishedbJ)Wm.M.Baxter, Jr., OfficialGuideoftheIsthmianCanalCommission.""NOAVEJlYSUPPLYCO80STON.,j