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11477. Geography.-We are looking south from
a construction trestle (like the one we see ahead of
us) built over the upper of the two sets of water-
elevators that enable a ship to climb up the fifty-five
feet between the sea-level ditch, which runs to Panama
City and its port Balboa, eight miles to the south, and
Miraflores Lake, behind us. Pedro Miguel Lock is
two miles to the north.
Transportation.-Construction.-A ship steaming in
from the Pacific will be stopped at the end of the
centre wall (to the right) where electric locomotives
will take it in tow. After it has passed through those
great gates ahead (the opening of which takes only two
minutes) it will still be on sea-level, but will be se-
curely caged in that great concrete tub below, one
thousand feet long, one hundred ten feet wide and
eighty-five feet deep. The walls rest on foundations
one hundred feet beneath the bottom of the lock. The
centre wall is sixty feet wide with vertical walls. The
side walls taper by steps on the .outer side from fifty
feet at the base to eight feet at the top.
The upper half of the centre wall contains three
stories of tunnels--the top one for the passage of
operators, the middle one for the electric wires that are
to operate the gates and the valve machinery of the 7
locks, the lower one for drainage. Through the lower
section of both centre and side walls run great culverts
(as large as the Hudson River tunnels of the Pennsyl-
vania Railroad), and from these smaller lateral culverts
run beneath the rock floors. From these, through
openings in the lock floor, water will be turned in to
raise the surface level to that of the lock above so the
ship can pass through the gates to the upper lock (be-
East chamber, lower locks, Miraflores. ,
Chambre de 1'est, les clausess du bas, Miraflofes.
Ost Kammer, niedere Schleusen, Miraflores.
Camara Este, compuertas inferiores, Miraflores.
Ostra bassiingen, liigre slussen, Miraflores.
BocTO Haa IaMepa, Hnamioie maio3, M paqjopec'b.
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