The Newtonian system of philosophy


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The Newtonian system of philosophy explained by familiar objects, in an entertaining manner, for the use of young ladies and gentlemen
Physical Description:
4, 137, 2 p., 5 leaves of plates : ill. ; 15 cm.
Telescope, Tom
Goldsmith, Oliver, 1730?-1774
Newbery, John, 1713-1767
Lisney, C
Walker, J
David Ogilvy & Son (London, England)
Vernor and Hood
Lackington, Allen and Co
Darton & Harvey (London England)
Printed for Ogilvy and Son, Vernor and Hood, J. Walker, Lackington, Allen, and Co., and Darton and Harvey
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Publication Date:
A new improved ed., with many alterations and additions, to explain the late new philosophical discoveries, &c. &c. -- by William Magnet.


Subjects / Keywords:
Science -- Popular works -- Juvenile literature   ( lcsh )
Scientific recreations -- Juvenile literature   ( lcsh )
Science -- Juvenile literature   ( lcsh )
Bldn -- 1798
non-fiction   ( marcgt )


Osborne Coll.,
Statement of Responsibility:
by Tom Telescope, A.M. ; illustrated with copperplates and cuts.
General Note:
Cf. Roscoe, S. Newbery, J348(8).
General Note:
Has been attributed to Oliver Goldsmith orJohn Newbery.
General Note:
Woodcut illustrations.
General Note:
Plates engraved on copper; frontispiece signed: C. Lisney.
General Note:
Advertisement, "A list of the optical and philosophical instruments mentioned in this book ... ": p. 2 at end.
General Note:
"Directions to the binder": p. 1 at end.
General Note:
"Price One Shilling and Sixpence bound."

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University of Florida
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The Baldwin Ubrary Rm B u n y

s IL Al



N E AV T 0 N I A N S Y ST L' --,Ivl





For the Ufc of



T11 I u fLyated I Lh Coppc plates a ii (I C tits.

1 7j-,h Many Altevations and A&I-ions, to exp1hia tile 13te nciv PhilofopLical Dit'covci ie, &:c. X-c.

L ON 1) 0 N:
Pr u'vd for (),,,dvv al)(1 Vemor and 11-,i; J. Walker; Lackington, Allii, and C,-.
and Darton and Harvey.

INTRODUCTION, page x. LECTURE 1. Of Matter and Mot;on. The Laws of Motion, page 5.-Attraaion
and Gravitationj 8.-Figure oftheEarth, q.-Magnet or Loadftone, i i.-Cohefion, m-The Sphere of Attraaion
and of Repulfion, 13LI CTURE 11. Of the U.;verfe, aizdjAarticularly of the Solar, vflem.
The Horizon, i5.-The Refle&ln,- TelefcOPe, 17.-The Refra&in- Telefcope, x8.-Fixed Stars, ig.-The Orrery 22.
The Sun and Planets, 23.-COU16S, 25.
The Moon and Tides, 25.-Eclipfes- of the Sun and Moon,26.-The Motion of the Earth, 3i.-TheArmillarySphere, 32.-The Terreftrial Globe, 33.-The
Seasons, 34--VelOcitY of Ll&ht,, 35LECTURE 111. Of the
and jVeteors.
.The Four Elements, 39.-The Air and
Atmofphere,+i-The'f ripleWcatherGlafs, 43.-Elafti it' of the I' r 45The Air-'Gun c' larthquakes',48Water,,&, __Light and Sound, 5o.-Echo, 5 i.-The Air-Pump, 52,-r-Ventilaors, SO.-The Air Balloun, 57-7-Winds, 0


C 0 N-1 T E NN T S.
-)Jifts, Fogs, Clouds, and Rain, 62.'I'hunder and Lightning, 63.-The Dectrical Machine, b4.-Snow and Haill, 67Zmrova Boyeol;sl or Northern Lialits, 67-1-nisFatiti iorjack-with-a-La- -.t--,.-n,69Rai nbow, 69.-H,110s, 70LECTURE IV. Of Alcilm4ins SArinp,
Riverss and thc Sea.
Avlountains, 7-1, -Burninor _N11ountains, 78
-Mount Etna, 79.-Hecla, go.-Ve11-1vius, 81-Springs, 8,2.-Rivers-an"'
Lakes, 84-The Sea, 85.
LECTURE V. Of Vegetab/e ,
and -1,i*)na1s.
Enyths, SS -Sand, Gravc], Earth, and
Rocks, go.-Foi'fils, go-%_'ul--ar and
Precious Stones, 90.-S al"s,
neralSut)f ir.cesgi.-Plartsg-.--Animals, ioi.-The Microf cope, i
LECTURENI. Of th. Ive Scn/es off
Man, and of hl Umdc ftandi 17'is t)y tj
Origin of our Ideas, m2.-Seeing 115ing C01_0L
Separate ne Prihn, iig.
Hearing 121.-Sm0ling, 122.-Taftin-,. 124.-Touching, 127.-Hcat and
Cold 12-I.-Pleafure and Pain, 12
Of the Underflanding5 131-,


Being the Subftance of



I AM defired by the Marchionefrs oF
Setfitar to give you fome account of thofe young Gentlemen and Ladies whom vou faw enter the faloon the morning you left us, and who came to his Lordfhip's feat on an adventure the moft extraordinary and the moft to be admired of any I ever knew. You may remember it was holidaytime, and thefe little gentry being come from fehool, met firft at the Countefs of Twilight's to divert themselves; wher they were fo divided in their taftei for amufements, that warm debates enfued.One proposed Threading the Needle, another Hot-Cockles, a third Shuttle-coc, a forth Blind Man's Buff; andatlaft ards
B *were

were mentioned. Mater Telefcope, a young gentleman of diftinguifhed abilities, fat filent, and heard all with complacency and good temper till this diverfion was propofed; blat then he started from his feat, and begged they wouldthink of force more innocent amufement. Playing at cards for money, fays he, is fo nearly allied to covetoufnefs and cheating, that I abhor it; and have 'often wondered, when I was at Bath with my Papa, how people, feemingly of years of difcretion, could fo far miftake themfelves and abandon common fenfe, as to lead a young gentleman, juft breeched, ot a little lady in a frock drets, up to a gaming table, to play and bet for fihillings, crowns, and perhaps guineas, among a circle of harpers. Parents,- continued he, might almost as well teach their children tothieve as to game: for they are kindred employments, and generally terminate in the ruin of both fortune and charaiEter.Lady Twilight, who is no friend to the modern modes of education, fmniled at this young gentle an's remark, and defired him to point out fne diverfion himfelf. 'Tis impoffible (9 me, Madam, fays hei to find out a cement f'uitabie to the tallfte
ofall th iany present, unlefs I was perfealy acquauted with their difpolitions; but

1troduilon. 3
but were I to chufe, I fhould prefer thrfe which not only divert the mind, but improve the understanding: andflch are many of the diverfiois at the Ichool where 1 at placed. We often play at flham Orations, comical Difputes, meafuring of Land and Houtes, taking the Heights and Diffances of Mountains and Steeples, folving Problems and Paradoxes on Orreries, Globes, and Maps, and fometimes atNatural Philofophy, which I think is very entertaining, and at the fame time extremely ufeful; for whether our knowledge is acquired by there amufements and reading little books, or by ferious and elaborate tfludy, what is obtained will be equally ferviceable: Iay, perhaps that which is acquired in the entertaining manner may have the advantage; for, as it is conveyed to the mind with a train of pleading ideas, it will be the more permanent and lasting, and the eafier balled up by the memory to our affiftance.
TheCountefs was very defirous of knowing what fort ofdiverfion could be de of Natural Philofophy: and finding her young vifitors in the fame difpofition, the condufed them to the ~arquis of Setflar's, that they might have the ufe of proper inftrmients. As my Lord Marquis was enB 2 gaged

4 Introdulion.
gaged in company, Lady Twilight, though nearly related to his Lordfhip, would not difturb him, but led them through the faloon into a private parlour, where our little Philofopher, at the requeft of her Ladyfhip, immediately opened the Le&ure, without making idle excufes, or waiting for farther folicitations; which he knew would be ill manners. *



Of Aflatter and Icfotion.

B Y Matter, my young friends, we mean
the fubftance of all things, or that of which all bodies are compofed, in whatever form or manner they may prefent themfelves to our fenfes; for this top, that ivory ball, the hill before us, and all things you fee, are made of matter differently formed.
As to Motion, I may fave myfelf and you the trouble of explaining that; for very boy who can whip his top knows what motion is.
Matter, or Body, is indifferent to motion or reft. As for example; when I whip my top, it runs round, or is in motion; but
wh en I icave off whipping, the top falls down, an4d Is at reft.
WheIn a body is in motion, as much force is required to make it reft as was re quired while it was at reft, to put it in orioi Thus: Suppoce a hov frikes a ballfrom a trap, and another thands clofe to c.atch it it will require as much firegt or force to flop that ball, or put it in a 14t of reft, as the other gave to put Itin
1B 3 motion;

6 Of Matter and Motion.
motion; allowing for the diftance the two boys fland apart.
No body or part of matter can give itfelf either motion or reft: and therefore a body at reft will remain fo for ever, unie s it be put in motion by fore external caufe; and a body in-motion will move for ever, unlefs fome external caufe tlops it.
This feemed fo abfurd to Mafler WVilfon, that he burfi into a loud laugh. What! fays he, flball any body tell me that my hoop or my top will run for ever, when I know by daily experience, that they drop of then elves, without being touched by any body? At this our little Philofopher was angcy, and having requested filence; Don't expofe your ignorance, Tom Wilfon, for the take of a laugh, fays he; if you intend to go through my courfe of Philofophy, and to make yourfelf :acquainted with the nature of things, you mufll ptepare to hear what is more extraordinary than this. When you fay that nothingtouched the top or the hoop, you forget the frifion or rubbing against the ground they run upon, and the refiftance they .. et with from the -air in their courfe, hich isvery confiderable, though it has c aped your notice. Soumewhat too mig

Of Latter and Mton. 7
be faid on the gravity and attra&ion between the top, or the hoop, and the earth; but that you are not yet able to comprehend, and therefore we fhall proceed in our Leaure.
A body in motion will always move on in -a straight line, unlefs ithe turned out of it by iomne external caufe. Thus, we fee that a marble fhot upon the ice, if the surface be very finooth, will continue its motion in a firaight line till it is ftopt by the friiion of the ice and air, and the force of attra ion and gravitation.
The fwifmnefs of motion is meafured -by ditanceof place, and thlcngth of time in which it is performed. Thus, if a cricketball and a fives-ball move each of them twenty yards in the fame time, their motions are equally fwift; but if the fivesball moves two yards while the cricketball is moving) one, then is the motion'of the-fives-ball twice as fwvift as the other.
But the quantity of motion is meafured by the fwiftnefs of motion -as above de fcribed, and the quantity of matter ed confidered together. F-or infancy Ift cricket-ball be equal in bulk andwe the fives-ball, and move as fiviff 'bth an equal quantity of motion. the crickct-ball be twice. a big heav<

S Of Matter and Motion.
as the fives-ball, and yet moves equally fwivft, it hath double the quantity of motion; and fo in proportion.
All bodies have a natural tendency, attra&ion, or gravitation-towards each other. Here Tom Wilfon, again laughing, told the company that Philofophy was made up of nothing but hard words.-That is becaufe you have not fenfe enough to enquire into, and retain the fignification of words, fays our Philofopher. All words, continued he, are difficult till they are explained; and when that is done, we fThall find that gravity or gravitation will be as eafily understood, as praife or commendation; and attraEion as eafily as correction, which you deferve, Tom Wilfon, for your impertinence.
Gravity, my young friends, is that univefal difpolition of matter which inclines or carries the leffer part towards the centre of the greater part, which is called weight or gravitation in the leffer body, but attra&ion in the greater, becaufe it draws, as it were, the leffer body to it.Thus, all bodies in or near the earth's furface have a tendency, or feeling inclination, to defcend towards its middle part or centre; and but for this principle in nature, the earth (confidering its form and fituatioa

'Of Matter and~ Moitiorn.
situation in the univerfe) could4'not fubfjf as it is, for we al fppofe threearth tobe nearly round (ny, we are fure it is fo, for Captain Cook, and' many ohr naig1tors', you know, have. failed .round tiI) aild as it is f~fp ded in fuch a mighty vi or fpace, and il"ways iri nmionbf,wht fhould hinder then Ilores, Water, and othcr parts ofdnater falling from the furface4 but the almighty armp of God, or this principle or universal laiw in nature, of attrac-~ tio$1 and gravitation,. which hie has efla blifhned to keep the univerfe in oder.-To ilUftrtC and explain what I have faid, let us fuippofe te following figure to be the


10 Of MAatter and Mot;on.
earth and feas: let Tom WVilfon land at this point of the globe or earth, where we are, and Harry Thompfon at the oppofite part of the earth, with his feet (as they muft be) towards us: if Tom drop an orange out of his hand, it will fall down towards Harry: and if Harry drop an orange, it will fall feemingly upwards (if I may fo exprefs myfelf) towatis Tomn: and if thefe oranges had weight and power fufficient to difplacethe other particles of matter, of which the earth is compofed, fo as to make way to the centre, they would there unite together, and remain fixed: and they would then lofe their power of gravitation, as being at the centre of gravity and unable to fall, and only retain in themfelves the power of attraction.
This occafioned a general laugh; and Tom Wilfon farting up, afked how Mafter Thompfon was to ftand with his feet upwards, as here reprefented, without having any thing to fupport his head ?-Have patience, fays the little Philofopher, and I will tell you ; but pray behave with good manners, Mafter Wilfon, and don't laugh at every thing you ,annot comprehend. This difficulty is folved; and all the freem. ing confusion which you apprehend of. ho, dies

OfAfatter and. Motloii. I I dIes fl y ing off from each other is remoIved!, by means of this attraLion and gravitation.,
_AILC any of the f'ailors whb have been~ round the world, and they will tell you thiat the people on~ the part of theglb over aga iift us, do not walk upon their beads, though' the earth is round; and though their heels are oppofite ours, they are in no more sOangrer of falling- into the mighty. fpace beneath them, than we are of falling (or rather rising, I muft call it here) upto the moon or the lars.
lint befides this aerieral law of attradlozv. and Cgravitation,~ Nwhiich affe&ts all bodies equal and univerfiflly, there are p I rticular bodies that attra& and repecl each otberl as mayv be teen byv this Maignet or Loadflone, which has the~ property of attra&ing or bringing iron to it with onec end,I and repelli!ng- or forci ng it aay w ith tho other. My knife, fays Samnes, which was rubbed on a loadftone forne years ago,. fill retains the power of picking up needies and. fMall pieces ofiron.
But this, falys MNIafft Telelkope, is btt a fmnalf, part of the virtues of the Lod ftohne ; for until its ufe was dificovered, faj.. lors never ventured with their Iips out O fight of land. You Cetinly joke Si fays Haurry Thouipfoi, fo it is impfi)

1 Of Matter and Aition.
that a piece of iron like that can be of any fervice in navigating thofe large hips I faw fome time ago. I am forry, replies our Philofopher, that you, like molt ignorant people, should think all things which you do not know the caufe of, imVoffible; but I will foon prove to you, that it's very fimple. They firft procure a piece of feel, made fomnething like a needle., but flat, about four inches long : this they rub with the Lbadftone, and then balance it exa&ly on two points or pivets, fo that it may turn round freely. One of the ends of the needle thus balanced, will always point towards the north. This needle, Nyhen put in a box, is called the mariners compafs. Thus the failors can fleer to any part of theworld; which they c6uid not do without the help of this piece of iron.
When bodies are fo attraaed by each other as to be united or brought into clofe contact, they then adhere or cohere together, fo as not to be eafily feparated: and this is called in Philofophy, the Power of Cohefion, and is undoubtedly that principle which binds large bodies together; for all large bodies are Imade up of atoms or particles incornceiveably finally. And this ohflion wiU be always proportioned to the

t1;mnber of4'particles or quantity ofthe 1frface of bodics'thit come ito corita&t, or toch each othcr ; for' thfe bodies that are of a lpherit4l form will not adhere fco ftrongly as thole that are flat or fctnaie, because they can wily touch each other at a cmraixn point ; and this is the reafon why the particles of iater and quickfilver, which are globular or round, are fo eafily f-epraatd with a touch, while thiofe of me.tals and f-me other bodies, are not to be Partedi but> with great force. To, give at fami~rarnfancc of this cohefion of mater, our Phiiofopher took two leadeni balls, and. filin~ga part off-each, fo0 that the two flat parts eight come ito clofe contact, lie 1;ently preffed themn 'together, aind thety
-united fo firmlyv,that it required foine confiderable force to get tlheni af-under.
The famne force applied to two diiferentbodies will always produce thec fame pianitity of motion in, Cach of them. Tio prove
OlWe put N1 P1 Jon~es into a boat,
Uyhich. (including, Ili n weight) wveighed ten-hundred, on the haheicsby the Mi11lbantk; and on the LamlAeth fide, 3juft Op, pofite, we placed another r boat of one hundred wveight, with a rope tied to it.Thi's rope Mafter jone.s pulled ia 'te qathc; boat; a~d we qbfcrv-ed, thait Ztl~

14 Of Matter and Motion.
boats approached each other, the fmall boat moved ten feet for every foot the other moved: which proves what I have before observed as to the quantity of motion.
Attra&ion is the stronger the nearer the attra&ing bodies are to each other; and in different diftances of the fame bodies it decreafes as the fquares of the diftances between the centres of thofe bodies increafe.. For if two bodies at a given diftance attra& each other with a certain force,--at half the diftance they will attra& each other with four times that force.



Of the Unilverfe, and particular of the
So/lar Syftenz.

Tf'HE IA~ Le&ure wa's read at the MarIquiis of Setfiar's, who wras fo well Pleafed at tihefe young gentlemen meetings thus to improve themnfelvcs, that lie or4leed them to be elegantly treated with tarts, fieetmeiats, fyIIahubs, atnd fuch colier dainties as his LorYdflp thought werec mnofl proper for youth : the Mardhionefs did themn the honour of her company, and I,~as particularly pleafed with the conver.fatioa of Mafter Telefcope. As it was a mnoonligh~t night, her Ladyfhiip, after fupper, led themn to the t* of the manljon, where his Lordthi has an obfervatcry, furinied with all ij~iltrumcnts neceffary for afironomical Wphilofophical obfervations. When the company were etd
-our Philofopher thus began bins feovd LecLook- round, my dear friends, fay, e youfee the c -h I' es to be bounde at

x6 Of the ,dor
hn equal difiance from us every way, and appears to meet the Iky h1v ich forms this beautiful ar-ich or concave over our heads. The Heavens declare the glory of GoD, and the firmament thewcth his bandy work," as the Ptailfnit beautifully exprelfes it. Now that dif-int round where we lofe fight of the carth, is called the horizon; and when the fur, mottr, and flars emerge from beneath and come into cur fight, we fay they are rifen, or got above the horizon; for all this glorious canopy befpangled with lights, that bedeck the Sky and illuminate the Earth, as the Sun, the Fixed Stars, the Comets, and, Planets (to which laft our Earth and Moon belong) have all apparent motion, as may be perceived by the naked eye; though, in fad, none move but the planets and comets; as will be proved hereafter.
But befides the fars which we fee there are others not discernible by the naked eye, fome of Awhich e fixed flars, and fome are bodies mov~bout the moft diftant planets, which were invifible -and unknown to us before tlhe difcovery of Telefcopes.


Of the FTnivefe.
Pray hand me that Refleffing TelcfT>

Tc youii- Pliiloioplicr taking A, and V:!6p it upon the tabic, gave the followTdcj'copefrom its conftru'lion, fpal iT' Illore INN any O'ller kind. It
I Cie, two llictallic f-pcc, cWiraHls' Vvitli'll f) Ua lar,- : -md a finally one. Thel-e, wilh two M.Ifles coitalncd in the fiDall t-ibe- marku, -B, ferve 1-0 tc- rcllc&- and vcf --ft the ravs of ll ',ht flfuir- from thc &.jcl", as zo fi uw flieni undcr a ma-nifletl C 3

'8 Of the TUniverfe.
appearance. In ufing the Telecope, to adjuft it exaaly to your fight, you turn the long crew C on the fide, while your eye is looking through at B, and the end A turned towards the obje&, till you can fee the object you want to examine in the moft perfect manner.
In the Refraaing Telefcope, which conflits- of glaffes only, diflant objeas alfo feem to be both magnified and brought nearer to the fight. The large end muft be placed pointing toward any difiant obje& which we wifh to fee more diftintly. In the other ed is a tube which flides within the Telefcope, and is adjusted to the proper distance by gently drawing it outwards. Now, if you look through the glafs at the end of this tube, to that part of the heavens, to which I have pointed it, or indeed any other part, you will perceive more ftars than you faw before wvithl your eye alone. Thefe are fixed flars, and are.called fixed, becaufe they always keep the fame distance from each other, and the fmc diflance from the fun, which is alfo

6f~k the tef
alfo ijied; and were he plated at theC imne fl iance they are at, would probably appear no bigger than onie or them.Pence fomne philosophers have concluded, and I think not without reafon, that every fixed ftar is a fun that has a fyftemi of pla-~ Inets revolvinga round It, like- our folar fyftemn. Anid if fo, how inImenfely -Ireat, how w-onderfully glorious is the firualure Of this univerfeC, which contains many thotifaind worlds, late as ours, fufpendedl in nther, rolino' like the earth), round their feveral Thins, and filled with animals, pants, and minerals, aill perhaps different from ou~rs, but all intended to ma-,gnify the Almnighty Archite3 "who weighed the "mountains in his golden fcakes, who "meafured the ocean in the hollow of his ~hand, who drew out the heavens as *a "curtain, who maketh the clouds his cbaSriot, and walke-th on the ings of the

The fervor and air of piety with u~hch
-hre delivered this. filenccd all his comnpanions, atnd gave infinite fatilsfa(Sion to thet Mvarchionefs. Mlafler Wilfo'n, who had iefore been very lipertine~nt, 1beg an DOWto confider hinifelf at fool in comrlkn to. ir I'hillofphcx; and as Maiter Telef-Cope' had

so Of the Univerf,
had mentioned the folar fyftem, he begged that he would explain it to him.
That I will with pleafure, replied the Philofopher, if you will be kind enough to hand me that Orrery that is in the corner of the obfervatory, and place it on the table; but firft let me obferve to you, that of thefe heavenly bodies fome are luminous, and lend us their own light, as doth the Sun and Fixed Stars; while others are opaque and have no light of their own to give us, but refle& to us a part of the light they receive from the fun. This is particularly the cafe with refpe& to the planets and comets of our folar fyftem, which all give us a portion of the light they have received,' and we in return refle& to them a portion of ours; for I make no doubt but thofe who inhabit the moon have as much of the fun's light refleled to them from our earth, as we have refleaed to ut
-from the moon.
The inhabitants of the moon fays Mafter Lovelace, with fome emotion ; whither will you lead me ? What! are the ftoeries that have been told of the Man in the Moon, then, true ?
I don't know what flories you have heard, replied the Philofopher; but itis n1o

Of the Un;VtIf".
Sib extraVpaant con
ZD Je6l ure to fu ppofe th at
the moon is inhabited as well as thc 'Caah ;,though -w1i'at fort of inhabitants thcy are,, we on e:irth, are umblc to dlfcover.As to. n Part, I am loft In this'l)(Yund1cfs
Lbyfi. t applears to me that the fun, which gIves llfc to the world, is only.a I)-eatil of the glory of God alid the wLich fupportsthat life, is, as it were, the brdt" Ils noffrils.
Dotili, u, 0 ( od support me vvhilc I gaze Itll af u
- tojilfhment at thy wonderful prodlirlons ; fiftce it is not idle irripcrtipent curlofity tivat leads rne to this enquiry, but a fervent desire to fee only the skirts of thy -lory, that I inay magnit
0 Y
thy power and thy mercy to mankind.



Of the Solar Syflem.

Now, by means of this Orrery, I will illuffrate our Solar Syftenm ; which contains the fun (marked a) in the centre, and the planets and comets moving about it.
f d ba ce g

But how is it then, fays Tom Wilfon, that we daily fee the fun rife and fet?
Your queftion, replies Mater Telefcope, is very natural; for it was an opinion held by the ancients fome thoufand years, that the earth was the centre of the UniverfC,

The Solar

Of the Solar Sflcm. *'
verfe, and the fun and planets revolved round it; but I think this is easily refuted by a common occurrence in a kitchen; I mean a fmall bird roafting on fpit before a'large fire. Would not you t ink it very abfurd if the cook hould eU#leavour to nake the grate with a large fire move round the fmall bird on the fpit?
Certainly I should, answers Tomn Wilfon; for furely it would be better for the bird to turn round before the fire, than the fire to turn round the bird.
Very well, then, fays our philofopher, the fun being more than a million times larger than our earth, we have certainly reafon to believe that it is the centre of our fyftem, and the earth and other planets move round it. But you will under fland this better if you look at the plate I have drawn of the fun and the planets, in their feveral orbits or circles, with their refpe&ive diftances from the fun, and from each other; together with the orbit of a comet.
The planets, as I have already obfcrved, are bodies that appear like flars, but are opaque ; that is, they have no light in th elves, but receive it'from the fun atnd ref it upon us. Of thfe there are two 'kinds:

24, Qf the Solar Svft em
kInds: the one called Primary', and tim qther S-condary planets.
There are feven primary planets; anc! thiefe aire mnarked on the Orrery as follows:, Mercury b, Nenus c, tl~e Earth d, Mars e,.
juptcrf, aturn g, and the Georginin idus (which beigg of fuch recent difcavery, is not represented, in this Orreryi) The laft of thefe was difcovered only x few years fince by Dr. Herfiliel, and called by him, out of refpe& to his preftnt Ma. jefty King George J1L. the Georgigtm Sius, or Georgian. All which move round the fun, as you fee by my turning' the winch of the Orrery; whereas the fecon4..
planets move round other planet.The, Moon, you know (which is one of the fcnayplanets) moves round the~ farth; four moons, or fatellites, as they are frequently cailed,.move round Jupiter; yi e round Saturn; and only tw,,o have yet been difcovcred to move round the Ceor-. pan i; though we have great reafont to be lieve. there are snore-; but from- the im1menrfe diftance of that planet, we have not yet perceived them. Thus has thie Almighty provicled light for tholt regions that lie at fuchl an imnenfce dftancefu

-the fun.


Of -the Solar SyiJ.m'
I have here made out a table of th periods, diftances, and diametr ftef veral planets. It~so ~ e
Revvlves round Dlllnc~fiom D!ea
the Sun in theSkun in i ~' years, days. Eiig. NMim MNies
Mercury o) 88 36,-oooc' 3z61
Venus C) 224 68p,oce-0 7699
Earth i or _365 9 .93,oooIooo 7c,20
Mars I & 31, 145,0 -),Gco 531z
jupiter I I- 3T4 49,,0.9"25 3 Satan 2,- 167' q96,coo,co, oc f Ls Georgian 83 -122182.G;0 34217
They all move round the fun from- Well to eall; but in their progrefs do not deferibe a pe6rfe& circle, but an orbit a littie inclining to an oval; the reafon wShereof I fhiall give you in a future Leaure.
The knowledge we have -of cot-ets i 'very iperfe&; it is a general fu1ppofitiorn that they are planetary bodies foriing a
-part Of our fYliemn, for they revolve about they fun in extremely long elliptic curve, being Ifoinerimnes very near 'it, at oth,-rs e~xtend Ing far, beyondc the fphere ofth cr gian. The period in revolving aout the ,funl, of one which appeared in 1 68o, Is
-compt ued to be 57 years.
Bu let us qit thefe bodies, of whili
we riw f ltteand fpeak of bur old
porp~nn-the1 Moon, with whom we
9u t 4 better acqantcd ; lice ih;

26 Of the Solar Syflem.
not only lights us home in the night, but lends her aid to get our tfhips out of the docks, and to bring in and carry out our merchandize; for without the afliftance of Lady Luna you would have no tides. But more of this hereafter.-A little more now, if you pleafe, fays Tom Wilfon. What then, does the moon pour down water to occasion the tides ? I am at a lofs to underftand you. No, replied our philofopher, the moon does not pour down water to occafion the tides; that were impoffible: but the, by attracting the waters of the fea, raifes them higher; and that is S the reafon why the tides are always governed by the moon.
The Moon's diameter is 2, 16o miles; her
diftance from the earth is 240 thoufand miles; fhe moves round it in the fame manner as the earth does round the fun; the performs her fynodical motion, as it is called, in 29 days,, 12 hours, and 44 minutes, though the periodical is 27 days, 7 hours, and 43 minutes. By this motion of the moon are occafioned the eclipfes of the fun and moon, and the different appearances, afpe&s, or phafes the at different times puts on: for when the earth is fo fituated between the fun and the moon, that we fee all her enlightened parts, it is F ull

Oflr Solar Syflen. 7
Full Moon : when the moon is to fituated between the fun and the earth, that her enlightened parts are hid or turned from us, it is New Moon; and when her ituation is fuch that only a portion her enlightened part is hid from us, we fee a Horned Moon, a Half Moon, or a Gibbous Moon, according to the quantity of the enlightened part we can perceive.
But I will codeavour to explain this to you more clearly, fays our philofopher, taking an ivory ball furpended by a firing, in his hand; we will fuppofe this ball to be the moon, the candle the fun, and my head. the earth. When I place the ivory ball in a dire& line betwixt my eye and the candle, it appears all dark, becaufe the enlightened part is oppofite the candle but if I move the ball a little to the right, I perceive a fireak of light, which is like the New Moon; if the ball is moved further it presents the appearance of a Half Moon; move it flill further, until all the enlightened part is feen, it appears like a Full Moon. I
I think it is extraordinary, fays Tom Wil-on, that the Moon which you fay is to much fmaller than the Sun, should appear to our fight equally large. T D2 That

23 Of the Solar Syflem.
That is eafily explained, replied our Philofopher, for if you confider that the fun is at 400oo times a greater diflance from us than the moon, your objeaion is anfwered; but this I will explain further in treating of Eclipfes.
I have frequently obferved, fays Mafter Lovelace, that the moon appears much larger when juft rifing above the horizon, than fle does afterwards; I should like to know the caufe of that. I thank you for your obfervation, Sir, replies our Philolopher; it is occafioned by the fogs or exlhalations that arife from the earth, which always magnify obje&s feen through them; thus the moon, until the rifes above there fogs, always appears larger.
The total or longeft eclipse of the moon happens when the earth is direly between the fun and the moon, and prevents the light of the fun from falling upon and being refle&ed by themoon; as youwill underitand by looking at the figure I have here drawn.

Of the Solar Sy2enr. 29

We will ftppofe the candle a tobe the Sun ; the cricket-ball h, to be the Earth; and the fives-ball c, to be the Moon. A firing being tied to each of the balls, I tie them up to the ceiling, or any other fup port, in a dire& line from the light of the candle; the cricket-ball about eight inches from the candle, and the fives-ball about two inches from the cricket-ball. Whenever the earth and moon come in the polition of the e balls, a total eclipfe of the moon enfues; becaufe the light of the candie (or fun) fhiining on the cricket-ball (or the earth) totally oblfcures or eclipes the fives-ball '(or the moon); but if w move the fives-ball a little higher up, or lower down,f to that the light from the candle may'pafs by the cricket-ball and tin upon part of the fives-ball, it will of cose be only partially eclipfed.
S3 All

Of the Solar Syjem.
An Eclipfe of the Sun is occafioned Fy the moon's being betwixt the fun and the earth, and preventing the light of the fun from coming to that part of the earth we inhabit.
This may be explained by changing the places of the balls; for when the fives-ball is in a dire& line betwixt the cricket-ball and the candle, it wit fhew a total ecliple of the iun; but if the cricket ball is moved a finally degree higher up or lower down, fo that the light from the candle fhines a little upon it, it will fhew only a partial eclipse.
But I should be glad to be informed, fays master Lovelace, how the fun which is fo inmuch larger than the moon, can be totally eclipsed from our fight, by the moon coming betwixt us and it?
That is what I intended to explain to you, replied Mafter Telefcolipe. If you place your cricket-ball in a dire&'line between your eye and the fun, it will entirely hinder you from feeing it, although your ball is much smaller than the fun.
An eclipfe of the fun never happens but at a new moon; nor one of the moon but when the is at the full.
The Moon confifts of Mountains and Vaflies, not unlike our Earth, and apFear

Of the Solar Sy4m. St
pear very beautiful when feen through the Telefcope I fhewed you fome time ago.

The livid fpots and bright freaks of light are fuppofed to be the mountainous parts ; and thefame parts being conftantly turned towards the earth, the always prefents the fame fide to us. The dark parts were formerly imagined to be feas; but from later qbfervation it is proved, that they are hollow places or caverns, which do not reflef the light of the fun.
The Earth, by its revolution about the fun in 365 days,S hours, and 49 minutes, rneafures out that fpace of time which we call a Year; and the line deferibed by the tarth in this arjual rcvoqut94 about the

3 Of the Solar Syem.
fun, is called the Ecliptic. By an infpection of this ArmiUlary Sphere you will have a perfe& idea of this and other circles neceffary to be known,

The annual motion of the earth round the fun is from weft to eaft, or, to fpeak more philofophically, it is according to the order of the figns of the Zodiac; which we Shall hereafter explain,
But besides this annual motion or revolution about the fun in the line of the Ecliptic, the earth turns iound upon its own axis in about 24 hours ; fo that it hath two motions at one and the fame time.
The Marchionefs; whofe curiofity had kept

Of the Solar SI~ecm. 33
kept her there during the Leaure, defired to have this explaineck-That tihall be done, Madam, in a minute, fays the littie philosopher; and I can never have a better opportunity, for I fee the Duke of Galaxy is coming on a vifit to your Ladythip; his coach is juft entering the iron gates, and will prefently wheel round the circle, or rather oval, before the portico. Pray, Madam, fix your eyes on one of the wheels (which you may do as it is moon-light) and you will perceive it tura round upon its own axis, at the fame time that it runs round the oval before thehoufc This double motion of the wheel very fitl$ represents the two motions of the earth.
By means of this Terreftrial Globe


4 Of the Solar Syfvem.
fthall explain more interesting afironomical principles.
YourLadyfhip knows perfectly that the earth, turning on its own axis, makes the difference of the day and night; you will therefore give me leave, Madaim, to addrefs my difcourfe to thefe young gentlemen and ladies, who may be ignorant of this branch of philofophy.
That the turning of the earth on its own axis makes the difference of day and night is moft certain; for in thofe parts of the earth which are turned toward the fun it till be day; and of courfe it muft be night in thofe which are turned from it.
But the length of'days and nights, and the variations of the feafons, are occafi6ned by the annual revolution of the earth about the fun in the Ecliptic; for as the earth in this courfe keeps its axis equally inclined everywhere to the plane of the ecliptic and parallel to itfelf, the earth in this direction has fometimes one of its poles neareft the fun, and sometimes the other. Hence heat and cold, fummer and winter, and length of days and nights. Yet notwithstanding there effe&s of the fun, which gives us light and heat, his diftance fromrn us is fo great, that a cannon-ball would be twenty-five years coming from thence

Of the Solar Sifem.
thence to the earth, even if it flew with the fame velocity as it does when it is firft difcharged from the mouth of a cannon.
Here they were all amazed; and Lady Caroline faid this doctrine could not be true; for -f the fun were at that immenfe distance, his light could not reach us every morning in the manner it does.-I beg your pardon, Madamn, replied the philofopher, your Ladyfhip's mistake arifes from your not knowing, or at leaft not confidering the amazing velocity of light, which although coming from the fun, which is 3() millions of miles diftance, reaches ui in the face of feveo minutes and a half, it mnuff in confequence travel at the rate ort about 80,000 miles in a fecond of time.
But if you are fo furprifed at the fun's diftance, Madam, what think you of the fixed fiars, which are fo far remote from us, that a cannon-ball, flying with the fame velocity as when first difcharged, would be 700,000ooo years in coming to the earth ? Yet many of there f ars are feen even without the Life of' telefcopes.
There are other things observable in our Solar Syfiem, which, ifattended to,,wiRL excite our admiration :fuch as the dark fpots which are feen on the Sun's fuf and which often change their place, ber.

36 Of the Solar SYem.
ber, and magnitude. Such alfo is the amazing Ring which encompaffes the body of the planet Saturn ; and fuch are the belts that gird the body of Jupiter :-concerning all which there are various conietures; but conje&ures in philosophy are rarely to be admitted-.


( 37 )


Of the Air, tmnofhhere, and Afors.

W HAT was faid by the Marchionefs
and Lady Caroline in favour of Mafter Telefcope, excited the Duke of Galaxy's curiofity to fee him; and the next morning he came into the Obfervatory juft as the Le&ure began. The prefence of fo great a perfonage as the Duke put the young gentlemen into fome confufion, and feveral of them offered to go away; which the Duke observing, fltepped into the next room; and Mafter Telefcope took this opportunity to corre& their folly.
Gentlemen, fays he, I am amazed at your meanness and ill manners, What because the Duke does you the honour of a vifit, will you run away from him?There is nothing betrays a mean fpirit and low education fo much as this ridiculous awe and dread which fome people fhew in the company of their fuperiors; and betides, it is troublefome; for the uneafinefs one perfon is in, communicates itfelf to the reft of the company, and abridgep them of a portion of their pleaIurc. The
E cafiet

38 Of the Air, ,tmoffhere,r eafier you appear in the company of the great, the more pqlite you will be efteemed. None but a clown hangs down his head, and hides his face; for a gentleman always looks in the face of his superior when he talks to him, and behaves with openness and freedom. As to my part, I venerate his Grace ; but then it is for his great worthinefs of charaaer, which has engaged my affe&ion, and inclines me to with for his company, not to avoid it.Civility we owe to every one, and refpe& is due to the Great: it is claimed, and it is given, in confequence of their fuperior birth and fortune, but that is all ; for our affe&ion is only to be obtained by worthinefs of charaaer. Birth and fortune are merely accidental, and may happen to be the portion of a man without merit; but the man of genius and virtue is ennobled, as it were, by himfelf, and is honoured not fo much for his grandfather's greatnefs as his own. This reproof had its proper effea ; for they all fat down, and his Grace being returned with Lady Caroline, our Philofopher began his Leaure on -the Nature and Properties of the Air, Atmofphere, and Meteors contained therein.

Of the Air, Atmofhere, &c~ 39
We have already considered the Earth as a planet, lays he, and obferved its diurnal and annual. motion; we are now to peak of the materials of which it is conipoled, and of the Atmofphere, and the Meteors that furround and attend it. SIn order to explain there effe&ually, fays
the Duke, you should, I think, Sir, begia with an account of the firlf principles of the four Elements, which are Fire, Air, Earth and Water, and then fhew how they affe& each other, and by-their mutual aid give motion, life, and fpirit to all things; for without fire, the water would affume a different form, and become folid ice; without water, the fire would fcorch up the earth, and deftroy both animals and plants; without air, the fire perhaps would be unable to execute its office; nor without air, could the water, though exhaled by the fun into clouds, be difribIted qver the earth for the nourifihment of plants and animals. Nor is the earth inactive, but lends her aid to the other elements; for fhe, by reflexing the fun's beams, occafions that warmth which nourifhes all things on her furface; but which would be very inconfiderable and fiercely felt, if a man was placed on the higher rountain, above the common level of the earth,
E 2 and

40 Of the Air, Atminfzihere, &c.
and in fuch a situation. as to be deprived of her reflefion,
All this, my Lord Duke, I have confidered, replied the Philofopher; and had thoughts of carrying it farther, and hewing how thofe.elenments pervade and are become indeed conflituent parts of the fame body for Fire, Air, Earth, and Water, are to be drawn even from a dry flick of wood. That two flicks rubbed violently together will produce fire, is very well known; for coach or waggon-wheels frequently take fire when not properly clouted with iron, and supplied with greafe; and if pieces of wood, feemingly dry, be put anto a glafs retort over a furnace, you'll obtain both air and water; and then if you burn the wood to afhes, and waflh out the falts with water, as the good womes do when they make lye, the remaining part will be pure earth: and thus we can at any time draw the four elements out of a flick of wood. But as there fpeculations are above the comprehension of fome of the young gentlemen whom I have the honour to inftrua, I fhall defer the confideration offich minute and abfitru1e matters till another opportunity. Science is to be taught as we teach children the ufe of their legs; they are at firft hewn how to

Of the Af'r' A4tmofPhC)er &c. 41 to ftand alone; after this, they are taugTht to walk within fafety, and thien fnff~red to run as faft as tbhey pleafe -: and. I beg youir Grace will permit me to pursue this muethod in the co'urfe of my L El1urcs. The Duke gave his affent wi a nod; and our philofopher thus proceeded : The Air is' alight, thin, elaffic or fpringy body, which may be felt hut not feen ; It is fluid, and! runs in a current like water (a9 you may Perceive by opening the window) butit cnnot, like water, be conge aled into Ice: and tile Atmofphere is that great body or ihell'of a':r which furrounds the eai th, and which reac-hes mnanv miles above- its f'urface, as is kvnby c-onfiderinZ the elafticiry or fpringuiiefs of the air and its weight together; for a colunnof air is of equal weight to a column of quickfiiver of bet-;%een 29) and 30 inches
high. ow qu -,,:.xr being near four t imes heavier than waeif the Air- was as heavy as water, the Atmuoifphere woud be about fourteen times higher thi~ii- the column of 9uickfilv 7, or about -,4 tf et; but the Air is near YGO1me tighter than wa,'ter; therefore the Atmoi kter- mruf b MAny1 rifles high, event this rate of .orfipottig. And when with this you conf12cr the: elafticity-of the Air, which, when the
E 3pefr

42 Of the Air, Atmiff here, &c.
preffure of the incumbent Atmofphere is taken off, will dilate itfelffo as to fill more than 15o times. the fpace it occupied before, you will perceive that the height of the Atinoafphere muff be very great. For as th Air is a fpringy body, that part next the earth muft be more denfe than the up4 per part, as being preffed down by the air above it. Look at that hay-ftack yonder, which the groom is cutting, and you'll perceive that the hay at the bottom is much clofer and harder to cut than that at the top, becaufe it has been prefled into a lefs fpace than it otherwise would have occupied, by the other hay above it; and had not the whole ftrack been trodden and preffed down by the men who made it, the difference would have been fill more confiderable.
The air, however, even hear the earth, is not always in the f-ame late. It is fometimes rarefied, and becomes lighter than at other times, as appears by the quickfilver's falling in the barometer, and the rains defcending on the earth.

Qf thie Air, Atmofiihere, &<. 43
It may be acceptable here, fays the young Philofopher, to explain the conftru&ion of that triple a
weather-glafs that I fee hanging up before me. So walking up to it, he de- b
fcribed it in the following manner: The uppermoft infirument contained in the round brafs box, is called the Hygrometer, (marked a). It confifts of a brafs plate, divided c
into degrees both ways, right and left, from o to 18o. To the left is engraved Afo/fl, and to the right Dry. In the centre of the plate is fixed the beard of a wild oat, with a piece of firaw glued to it, as an index. The Index is firft fet to 0 of A
the divisions, fo that any change of the air which happensafterwards in the room to A!Mo) or Dry, the beard by twifting or untwifting itfelf from the action of the air, will by the Index point it out accordingly on the fcale.

44 Of the Air, ZtmafJkere, &c.
The. open fquare part next below, is called the Barometer, (marked b). It confiftlls of.a glafs tube about 32 inches long, clofed at the top, firit filled with quickfilver, and then inverted on a reservoir or leather bag below, of quickfilver. By this means the quickfilver inlthe tube fubfides to its proper height, as a&ed upon by the preffure of the air, or atmosphere ; for it is the denfe fate, or heaviness of the air, that raifes the quickfilver in the barometer, and prevents the clouds from diftilling through the air in rain; and, on the contrary, its lightnefs that admits the fall in showers, &c.
Barometers are alfo ufed to determine the heights of mountains, &c. becaufe as we afcend, the quickfilver rifes in proportion; the weight of the atmofphere which preffes on it being lefs.
But what is the ufe of that ferew at the bottom of the inftrument ?" fays Mafter Wilfon. I thank you for the question, fays the Philofopher; for many a young ignoramus has totally fpoiled a good barometer, by foolifhly playing with that fcrew till they forced it up, broke the bag, and let out all the quickfilver. Let it be particularly known, that this fcrew is only provided by the inirument-maker, to force "p

Of the Ar, AtmofP here, &c. 45
up the quickfilver in its tube in a gentle manner, fo that in conveying the inftrument into the country or abroad, it is thus made quite portable, and not liable to have the tube broken by the concuffion of the quickfilver against the top of the tube. The next infirument below is called the Thermometer (marked c). It contains a long glafs tube, partly filled with quickfilver, and fcrewed down to a brafs fcale, on which are marked divifions and terms of various degrees of heat and cold, from boiling water down to freezing, found and adjusted by a&ual trial of the maker, The freezing point is marked 32, and the boiling water 212. This is called Fahrenheit's Scale, as being the name of the inventor. The heat of the air expands the quickfilver in the ball; and it accordingly rifes in the tube; whereas, on the contrary, cold contraas the qutickfilver, and it of course falls, fo that at any time by mere iiinfpection, the change of the temperature of the air is immediately fhewn.
Theelaftic principle in the air, which renders it fo capable of being rarefied and condenfed, has, beenprodu&ive of the moft wonderful effecs. But before you proceed farther, fays Lady Caroline, pray do me the favour, Si4, to convince me, by flome

46 Of the Afir, Atmofflkere, &c.
fome experiment, that the air is endowed with this wonderful quality.-That he cannot do, replied the Duke, without the dfe of proper inftruments.-Almoft any thing will do, an't pleafe your Grace, fays the Philofopher.-Little Mafter's pop-gun that lies in the window, is fufficient for my purpofe.-Do me the honour to Rfep this way, Lady Caroline. You fee here is a pellet in the top of this tube, made of hemp or brown paper. With this piece of paper we will make another pellet, and put it into the other end. Now with the gunRick drive it forward. There you have forced the pellet fome part of the way with eafe; but it will be more difficult to get it farther, because the air, being compreffed and made more denfe or compact, will make more refiftance; and when you have preffed it fo clofe that its force overpowers the refifiance which the pellet makes at the other end, that pellet will fly off with a bounce, and be thrown by the fpring of the air to a confiderable diflance.-There, fee with what force it is thrown!
This you have taken little notice of, becaufe it is a fchool-boy's action, and is feeti every day; for, indeed, we feldom trouble ourfelves to reafon about thins that are to familiar; yet on this principle, my

Oftl Ar, A fre; Mc. 47
mny Lady, depends the force of a cannon;i for it is not the gun-powder and fire that drives out the ball with fuch prodigious velocity; Po; that force is occa~ioned by the fire's fIuddenly rarefying the air which was contained in the chamber or breach of the cannon, and that generated by the power itfelf. As a proof of this, place the fame ball in the fame quantity of powder in an open veffel, and when fired you will farce fee it move. But there have been guns lately invented, called Air-guns, which abundantly prove what I have advanced; for they are charged only with concentrated or condenfed air.
k Iereis oneI perceive,hanging over my head, whete you are to observe that the bal, which is previously filled by a fyringe with the condenfed air, is ferewed under the back, and by pulling the trigger, a valve is pufhed in the ball by a pin the air, ruL hes from thence through the back into the bariel against the bullet, and drives

48 Of the Air, Atmofphere, &c.
drives itto a great diftance; and the air in the ball is fufficient to difcharge fix or feyen balls, one after the other; each of which would kill a buck or a doe at a very confiderable difiance.
You feem all amazed, and I don't wonder at it, fince you have never yet confidered the extraordinary properties of this element; and it muft feem firange to you that the air, which is fo neceffary for life, that without it we cannot breathe, should be tortured into an infirument of defiruction. You will, however, be more furprifed when I tell you that this is probably the caufe of earthquakes; and that the noble city of Lifbon was fome years ago deftroyed by a fudden rarefa&ion of the air contained in fome of the caverns of the earth, and perhaps under the fea.-Tom Wilfon gave a leer of impertinence, but was afhamed to fhew his folly before fuch good company. All the reft feared at each other without fpeaking a word, except Lady Caroline, who protected fhe could not believe what he had faid about earthquakes; for, fays fhe, I remember to have read in the news-papers, that the flames burf out of the ground. That might be, my Lady, fays the little Philofopher ; for there could be no fuch fudden rarefa&ion of the air without

Of the Air, Atmoffihere, &c. 49 without fire. Fire therefore did contri-bute towards the earthquake, and fire might burn down a mountain composed of coinmbuftibles; but fire could never blow one up. No, my Lady, that effed is the fole property of the air. This dispute would, in all probability, have taken up much time; but his Grace put an end to the controverfy, by declaring it was true philofophy.
In this property of being rarefied and condensed, the air differs amazingly from water, which, though compofed of fuach fmnall particles as not to be diftinguifhed or feen feparately with a microfcope, and notwithftanding its readinefs to rife or be evaporated with heat, and to be feparated with a touch, cannot, when confined, be at all concentrated, or brought into a lefs compafs.
I have already intimated that heat is the efficient caufe of all fluidity, and that ice may therefore be termed the natural fate of water; the utility of which to man, as well in diluting his food as in increafing his enjoyments in various modes, it would be tedious arid ufelefs minutely to defcribe to you ; containing a quantity of air, it is the medium by which aquatic aniinals refpire. It is alfo, if not the principal, at
SF leaft

50 Of the Air, Atmoffikdre, U. leaft a confiderable part of the food of Vegetables; which I will afterwards ex plain to you.
By increafing the heat, water is rendered elaftic and volatile; that is, is converted into vapour, the force of which when confined is almoift incredible.; this force has been applied to the ufe of Mechanics in the Steam Engines, by which it is fald, that a fingle drop of water, converted into vapour, is capable of raising feveral hundred weight. The conftruaion of thefe engines is fo very complicated, that it is impoffible for me to explain without a modeL
Air is the medium which diffufes light to the world; for if there was no atmoIphere to refra& the funim's rays round the globe, it would be almnoft as dark in the day-time as in the night; and the fun, moon, and ftars, would only be vifible.It is alfo the medium of founds, which are conveyed by the tremulous motion of the air when agitated by any noife. Let
-me throw this peach-flone into the moat, and you will perceive circles of-fmall waves diffuie themselves by degrees to a great distance round it. Now, as the air is fluid as well as the water, we may conclude that fouad is .conveyed somewhat in this manner; though as that is nearly a thoIaad tii es lighter than water, founds arc

Of the Air, Atmoff&ere, &c. 5
are propagated at an amazing rate: fome fay, after the rate of 1,142 feet in a fecond of time; but however that be, we may rcft affured that found is conveyed in this manner :-Only throw up the falh and halloo, and the echo will return you the found; that is, the waves or pu!fes of air, which are put in motion by the noife you make, will firike againft the rocks and return to you again: for echo is nothing but the reverberation of found. And that there can be no found conveyed without air, is proved by experiment; for a bell, firuck in an exhausted receiver in an air-pump, cannot be heard; that is, it has little or no found.
Without air there would be no merchandize; for your thips could not fail to foreign climates; and without air the birds .could not fly, fince they would have nothing to fupport them, and their wings would be ufelefs; for we know that a feather falls with as much velocity as a guinea in an exhaufted receiver of an airpump. But-above all, air is the principle which preferves life both in plants and animals; there is no breathing without air: and you know, when our breiathi is Slopt, we die. This is one of thofe -ri-t that are called felf-evident; becau it univerfally known, and needs o~ oni
V : ttc

52 Qf the Air, Atnoffhere, &c.
nation ; but if demonstration be thought neceffary, you may have it in a minute, by putting fome living creature into an airpump :-but, laid Lady Caroline, it is cruel to torture a poor animal; and violently oppoled this experiment being tried ; but as all the reft were for it, the Duke was willing to gratify thcir curiofity, and therefore told our philofopher that he might try the experiment with a rat, which they had caught in a trap; and if he furvived it, give him his life for the pain they had put him to. MafterTeletcope, after placing the airpump on the table, proceeded as follows:

d '' ,I

Of tileA, Amire, c.
By the help of this mnachine, all that I
bave fpoken concerning the wveignt and elaficity of the ait, is demonftrated1 in the moft fimnple and elegant manner. For by working thie handie-(markedl A) all rh~e air that is contained within the glaf's receiver (marked B) is pum-ped out; and if any living animal is put within the TeCeiVev, All the air In its body is pumped out likewife: then, as I mentioned before, air
-bngte principle which pref'erves life,
the anlimal dies, un.lefs frefh air' be imnleiaeyadmitted, which may be d one 6y turin a er w(at C), Our philofopher
then put the rat i nto the, receiver; and when.r the air wva; nearly exhaufted, it ap-, peared ingreat agony, and conv ul fed;, and more air being pumnped out, it fell on its fid-, for dead ; but ,f re h PaIr 1-, -_ i 1Lmed i* arel~ admitted, it ruied into its ligs'
which put them in motion again, and he recovered. The manner -of the animal's recovery I, puts me in mind, fays the philofopher, of an accident which once fawv, and which I would have you all remenmber ; for it may be of feorvice to mankind.
Some time ago I %v,.s bathing with fcveraT of my fchool-feliowvs in a river by the roa1d"-fide. Mailcer Curtis, who was anl obfiinte filly boy, would daRad tbe reift, E3as

54 Of the 4ir, Atmnzofpher c.
as he called it; that is, he would foolifhly exceed them in running into dangers and difficulties ; and with this view though he could fwim no more than a ftone,he plunged into a part of the river, which we told him was greatly above his depth, where he role and ftruggled to get out, but could not. We were all in thile utmoft diftrefs, and unable to affift him, for none of us could fwim. At this inftant fome gentlemen on horfeback came up, who immediately difinounted, and got him out; but not till after he had funk the third time.He was brought to the thore without figns of life, and blooded without any effect; when one of the geunemen, who I have fince heard was a great ph'iolopher, advifed them to blow fome air down his throat; this was done, and the elafticlt of the air put his lungs in motion, as i.MaIne, for a pulfation immediately enftu he recovered almoft as foon as this afal Now, from what heard that gentleman fay, and from the infance before us, there i -eafon to believe that the lives of many rght be faved, who are fuppofed drowned, i h method was put inprat&ice of con-veying ar to the lungs; for you are to confider, that unlefs the lungs are in motion, there can be no circulation; and it was for want of air

0f13' i,~tropiee c 55
r. ar that theCir mTotionl ceafed InI the- Water-.
Pray,. genitlemeni, let thIs, he remtiemberedj, for It Is a mtatter- of 'great I mportance.
We are to obfer-ve, gentlemni, that air which has paffed through fire, or is become foul or fiagnated, and hzs loft its fpring, is unfit for respiration. It was the want of frefhi air, or, in other words, the being oMIgtJd to breathe-air that was foul, and had loft its fpring, or elaffic force, that iome years ago killed fo many of our poor countrymen i n the 'black hole at Calcutta, in the Eaft lmndies: and this bieathing of foul air Ii iini ory, putrid, and eruptive dif orders. IL, For inifance, as the ifmall pox and foniem fevers, has deft roy ed more than can beiat nd If therefore yon 11-oid be feized with any of thefe, dilforders, advife the people about you to make ufe,- of their common fenfe, andrnpt,
nefea man is ill, deprive 'him of that.
Ita p-rinciple the air, witfiout which he could rot live, even in a flate of health. Never fuffer your curtains to be drawn dlofe1, or exclude the frefli air, even when Vyou fleep.
I aii greatly mitaen ays Lady Camoline, if the air wve are now inI has, not loA it', fpr' ngC; for I brCeathe mith difficulty. Was that the cafe, -Nladain, repliedth little

S6 Of the Air, Atmofihcre. &c.
little philofopher, you would not be able to breathe at all ; but if your Ladyfhip finds the air fo difpofed, you should make ufe of the infirument that lies by you; which, by putting the air in motion, will, in part, recover its fpring. What inftrument, Sir ? fays the Lady. Your fan, Madam, returned the philofopher. Every fan is a philofophical instrument, and was origipally contrived, we may fuppofe, for the purpose above mentioned.
A bird dying in an air-pump will be in fome measure recovered by the convulfive fluttering of its own wVin becaufe that motion alters the late of the air remaining in the receiver, and for a time renders it fit for refpiration.
Motion is the only preservative for air and water; both of which become unwholefome if kept long in a fate of reft; and both may be recovered and made falutarv by being again put in motion.
If foul and ftagnated air has fuch dire effe&s, how much are we obliged to the learned and ingenious Dr. Hales for dif. covering the Ventilator: an infirumentr which, in a little time, discharges the foul air from hips prifons, and other clofe places, and fu plies them with that'which is frefh!

Of the Air, Atmoffhere, &c. 57
The refearches of our modern philofophers, fays our Le&turer, have been the means of many new difcoveries in regard to air. They now produce and prove the' exiftence of many different forts of air: fuch as our common air, inflammable air, nitrous air, mephitic, more technically denominated by them gaffes or claftic fluids. But to convey to you a clear idea, would fuppofe fome knowledge of chemiftry in my readers. I muft therefore beg leave to difpenfe with the account of there now, and only to advife my hearers to a loudy of chemiftry as now improved, as a fcience that will afford them much pleafure and information in Nature's wonderful operations.
When you mentioned inflammable air, fays Mafter Wilfon, I thought you would have mentioned the Balloon; which, of all wonders I think the greatest.. I proteft it perplexes me to account how in nature it is poffible for any large hollow fubftance, even although filled with air, to float in the atmo fphere, particularly when weighed down with a boat and two men in it, as represented in this picture hung near me; which records the memorable event of Mr. Blanchard and Dr. Jefferies croffing

sIg the- eno
Frncte Eng fl Channel from Dover to

fays our philofopher.. Why, furely, yID.U never confidered the reafon of thoe balls that I have feen you make by foap and water beat to a lather, and--blown out of the bowl of a tobacco-pipe. "The air, by which they are blown, iffuing from your lungs, is fpecifically lighter than the comnznon air, even when contained in;;hat thin wate~ry globe. Now, inflammable air is About

Of the Ar, 4tmoP ere, c. 59
about ten times lighter than common air; fo that a large hollow filk balloon, filled with inflammable air, although loaded with a boat, two men, and fundries, is lighter in its bulk than common air; and confequently, when releafed from its cords that faften it to the ground, it rif-es majeffically, and foars along in and above the clouds, according to the direction of the wind.
We are now to fpeak of the Wind, which is only a stream or current of air, as a river is of water, and is occasioned by heat, eruptions of vapours, condenfations, rarefaEAions, the preffure of clouds, the fall of rains, or fome other accident that diflurbs the equilibrium of the air: for Nature abhors a vacuum, and for that reafon, when the air is extremely rarefied in one part, that which is more denfe will immediately rufh in to fupply the vacant places, and preferve the equilibrium; as is the cafe with water and other fluid fubftances. Onyiv raifea veffel of water fuddenly out of a ciftern, and fee with what feed the other water will rufh in, to fill up the fpace and preferve its level. And thefe rqefaaions in the air may happen near the earth, or much above it; and is the reafoa why clouds fly in contrary dirctaious

6o Of the Ar, Amofklhere, &c.
re&tions. This occafioned the lofs of the great kite, which we were a whole fortnight in making; for though there was fearcely wind in the park fufficient to raife it, yet when lifted extremely high by the air, it was feized by a current of wind, and torn in pieces.
Winds are violent or gentle, in proportion to the rarefalion or difiturbance there has been in the atmosphere. A violent wind, in a great form, fies after the rate of So or 60 miles in an hour, and is often fo denfe, or firong, as to bear down trees, houses, and even churches before it. What the failors call a brifk win(, flies after the rate of about i; miles an hour, and is of great ufe in cooling the air, and cleanfing it from poifonous and peftilential exhalations.
The winds have various qualities; they are generally hot or cold, according to the quarter from whence they blow. I remember, fome years atgo, we had a fouth-wet wind in February, which blew fo long from that quarter, that it brought us the very air of Lifbon; and it was as hot as in fummer. Winds from the north and' north-eaft, which come off large gas of land, are generally cold. Some winds moiften and diffolve, othersdry and thicken: lowne

Of the Air, Atmofjihere, &c. 6
fome raife rain, and others difperfe it: fome winds blow conifantly from one quarter, and are therefore called the General Trade Winds; there are met with on each fide of the Equator, in the Atlantic, Ethiopic, and Pacific Oceans. Some winds, again, blow conflantly one way for one half, or one quarter of the year, and then blow the cOntrary way. Thefe are met with in the Eafi indian feas, and are called Monfoons, or Periodical Trade Winds. But as there fubje&s are abflrufe and difficult, and afford little entertainment, I will defer an explanation of them at prefent, and endeavour to give you fome account of the Meteors that attend the air.
We have already obferved, that, besides pure air, the atmofphere contains minute particles of different forts, which are continually arifing in ftreams from the earth and waters, and are fufpended and kept floating in the air.
The moft confiderable of there are the fmnall particles of water; which are fo feparated as to be lighter than air, and are railed by the fun's heat, ot lifted up by the wind from the fea, rivers, lakes, and marfhy or moilfl parts of the earth; and which defcend again in Dews, Rain, Hail, and Snow.
G When

62 Of the Air, .Atmoffiere, &c.
When there fmnall particles are, by a rarefied ftate of the air, fuffered to unite many of them together, and defcend fo as to render the hemifphere more opaque, and by its humidity to moiften bodies on the earth, it is called a Mift. And, on the contrary, thofe particles of water that arife after a hot day from rivers, lakes, and marfhy places, and by fillingthe air moiften obje&s and render them lefs vifible, are called Fogs.
Clouds are the greateft and moft beneficial of all the meteors, for they ai e borne about on the wings of the wind, and, as the Pfalmift obferves, '" Difitribute fatncfs to the earth." Clouds contain very fmnall particles of water, which are railed a confiderable diftance above the furface of the earth; for a cloud is nothing but a mift flying high in the air, as a miif is nothing but a cloud here below.
That thefe vapours are raifed in the air, in the manner above-mentioned, may be readily conceived; for it is an a&ion that is feen every day in common difiilatiois; but how thefe invifible particles which float in the air, are colle&ed into clouds, in order to bring the water back again, is not fo caly to determine. It is probable, that

Of the Air, Atitoffihere, &c. 63
that by uniting firft into fall drops, then into larger, they become too heavy to be fufpended by the air, and fall down in rain.
We come now to defcribe the caufes of Thunder and Lightning; but here I mufll take the Ele8rical Machine to my aid.
On account of the many late improvements that have 'been made in the fcience of ele&ricity, the inftrument-makers have made ele&rical machines upon various con, firu&ions. The one I am now going to defcribe is not of the moft modern of there; but as the effential parts are exactly the fame in all, you will obtain by this a fufficiently complete and juft information of the curious properties belonging to them.
All the phenomena called Elearical, are fuppofed to be effeaed by an invifible fubtile fluid exiting in all the bodies of the earth. The Eleatrical Machine is made to extra& this fluid from the earth, in the manner I will defcribe to you.

G 2 The

64 Of the Air, Atmo4fzhere, &.

The handle (marked A) being turned round, by means of fome wheelwork in the box (marked B) turns round the glafs cylinder (marked C); this cylinder rubs again I the cufhion. of fluffed filk, which is called

Of the Air, dtnoffrhere,. &co (63

called the Rubber (marked D): by this means the elearic fluid is extra&cd from the rubber, and carried round by the glafs to the points (marked E) which it enters, and remains in the tin tube or conduaor (marked F), which is fixed upon a glafs flem (marked G): as the electric fluid cannot pervade glafs, this fitem hinders it from returning again to the earth. When tihe machine is worked, if a perfon places one of his knuckles about half an inch from the brafs knob'at the end of the condu&or (marked H) the elearic fluid will dart like a bright park of fire from it to the knuckle, and givethe perfon a mall degree of pain. IT, inflead of the knuckle, a coated jar is placed to the coiduaor, the fire will be received by it, and accumulated therein: fo that if a perfon touches the bottomn of the jar with one hand, and the bali at the top of it with the other, he will receive the charge of electricity through him, and feel the fenifation of a fudden fhock.
The fimilarity of lightning and ele&ricity is not to be remarked in a few appearances only, but is obfervable throughout all their various effe&s, Lightning defAroys edifices animals, trees, &c. it always goes through the beft conduors, fUch as metaklor water; btt if it eets
U q With

66 Of the Air, AZmyf//kere, &c.
with fubftances which will not condu& it, (fuch as ftone or wood) it rends them, and difperfes them in every dire&ion. Lightning burns, and often melts metals and other fubftances. All there effe&s, as I faid before, may be produced by ele&ricity. But befide the great fimilarityexifting between lightning and elearicity, what fully proves them the fame is, that the matter of lightning may be a&ually brought down from the clouds by means of elearical kites: but as this is a very dangerous experiment in unikilful hands, I will not now defcribe the method of making them. Clouds have almoft always fome ele&rical matter in them; and the lightning accompanied, which is fuppofed to be collected from the earth with the thunder, is only that matter darting from one- or more clouds into another cloud, or elfe upon the earth ; in which cafe it firikes upon the moft lofty and pointed places, and by this ftroke produces all thofe dreadful effeas that are known to be occafioned by lightning. But, lays Mifs Carolina, you have not yet mentioned thofe pointed rods on the tops of many large buildings ; I have been told they proteA the buildings from lightning. That they certainly do, Ma4an faid Mafter Telefcope, for the lightn111g

Of the Air, Atmnolihere, &c. 67 ning is attracted from the clouds by the pointed rod, and is by it condu&ed down the fide of the building to the neareft water without damrnaging it. There rods were the invention of the late ingenious Dr. Franklin, of America. People in general, when they happen to be caught in a thunder-ftorm, run for fhelter under a tree; but that is very wrong; for the lightning is attracted by the tree, and thus accidents often happen. The beft way is to get into an open "place and lay at a diftance all metal which you may have about you: if you do this, you are not in much danger of being hurt by the thunder and lightning.
Snow is the fimall particles of water frozen in the air before they had united into drops: and hail is drops of rain frozen in the -fall.
The Aurora Borealis, or northern lights, are occafioned by certain nitrous and fillphureous vapours, which are thinly spread through the atmofphere above the clouds, where they ferment, and, taking fire, the explofion of one portion, kindles the next, Iand the flahies fucceed one another, till all the vapour is fet on iire, the treams whereof feem to converge towards the zeit of the

68 f the Air, Antwmojhere, &c.
the fpe&ator, or that point of the heavens which is immediately over his head.
At this inftant, up tarted Mafler Long, and tbld her Ladyfhip, if fle had done, he wouldbe glad to aik aqueftion. Sir, fays tlhe, with a file, it was you made the compliment; I should be glad to hear your question, for, I dare fay, it will be a fenfible one. I wifh you may find it fo, replied he; but what I want to have an account of, is this fame Jack-with-a-Lantern, which fo haunts my Lord Marquis's park, and t'other day led my friend T om Wilfon into a large pond. Mailfter Wilfon, you're to underftand, had been at his uncle's, where he had faid rather too late, and therefore his uncle ordered the footman to light him home; but Tom, being a very courageous fellow, and a little ob. flirate, would walk home alone, and in the 'ark: and jutl ashecarnme intothe marfhymeadow, who should he almost overtake ut this fame gentleman, this Jackwith-i-Lantern, whom he miftook for GgoJY Curtis, the chair-wohan, and thought Uhe wa- lighting herfelf home from ,,ork. Tom ran to overtake Dame Cr- t bt Mr. jack with his Lantern
tit sc it out of reach, and led my friend Tomn out a the path; which he did not perceive

Of the A Zi, Atmrfpkere, &:. 6g perceive till he had lo himfelf: on which Tom ran and Jack ran; Tom haloo'd, and Jack would not answer. At aft oud came Tom into Duc 'weed pond, whre he might have lain t his time, if r, Goo tall had rt b ihm as
he was riding by, an t 6 ..- This put all the cor p.ny n good humour; and Tom had ctood nature and good fenfe enough to join them in the laugh; which being fubfided, our Philofopher thus proceeded in his Le&Eture:
The Ignis Fatuus, 7ack-with-a-Lantern, or PVill-with-the-Ivf, as it is frequently called, is fuppofed to be only a fat, un&uous, and fulphureous vapour, which in the night appears lucid; and being driven about by the air near the earth's furface, is often mniftaken for a light in a lantern, Vapours of this kind are in the night frequently kindled in the air, and fome of them ap pear like falling flars; and are by ignorant people fo called.
It may be here neceffary to mention that beautiful phenomenon the Rainbow, fince it has the appearance of a meteor, though, in reality, it is none; for the Rainbow iS occafioned by the refra&ion or refleSion of the fun's beams from the very iall drops of a cloud or mift feen in a certain n angle

7o Of tht A4r, Admoffiere, &.c.
angle made by two lines, the one drawn from the fun, and the other from the eye of the fpe&ator, to thofe fmnall drops in the clouds which refiedi the fun's beams: fo that two perfons looking on a Rainbow at the fame time, do not, in reality, fee the fame Rainbow.
There are other appearances in the atMnofpherewhich ought to betaken notice of; and thefe are the halos, or circles, which sometimes feem to encompafs the fun and moon; and are often of different colours. There always appear in a rainy or frofty feafon, and are therefore, we may fuppole, occasioned by the refra&ion of light in the frozen particles in the air.
Here the Le&ure would have ended, but a fudden clap of thunder brought on frefh matter for meditation. Some of the company, and particularly the ladies, endeavoured to avoid the lightning; but Mafter Telefcope, after the fecond clap, threw up the fafh, and affured the ladies and gentlemen there was no danger, for that the clouds were very high in the air. The danger in a thunder ftorm, fays he, is inproportion to the violence of the tempeft and the distance of the clouds; but this tempeft is not violent; and that the
cloud is at great distance, or h;gh in the
cloud~a ata :

Of the Air, Atmofphere, &c. 71
air, you may know by the length of time there is between your feeing the flafh of lightning and hearing the clap of thunder. Look, fee how the fky opens to emit the fire prefently you will hear the thunder; for you know we fee the fire from a gun at a distance, long before we hear the report. There' it is! and how tremendous! Thefe tempe(ts always put me in mind of that beautiful paffage in Shakefpeare's King Lear; where, when the good old King is out in a form, and obliged to fly from his unnatural children, he lays,

-Let the great Gods
That keep this dreadful thund'ring o'er our heads, Find out their enemies now. Tremble, thou wretch, That halt within thee undivulged crimes Unwhipt of juice 1 hide thee, thou bloody hand, Thou perjur'd, and thou fimular of virtue, That art inceftuous! Caitiff, fhake to pieces, That under-covert, and convenient seeming, Has pra&is'd on man's life! Clofe pent-up Guil, Rive your concealing continents, and afk Thefe dreadful fummoners grace!This tempeft will not give me leave to ponder On things would hurt me morePoor naked wretches, wherefoe'er you are, That bide the peklting of this pitvlef Iftorm I 1ow

yz Of the Ar, AjnaI2llhere,; &c. How Thall your houtfelefs heads, and tiofed, fides, Your looped and widowed raggednefs defend you From feafons fuch as thefe 3-O, I have ta'en. Too little care of this !Take ph) fic, Pomp), Expofe thyfeif, to feel what wretches feel, 'And thou mayfiake the fuperflox to them, 'And fliew the Heavens more juft.

( 3)


Of Mountains, Sl ings, Rivers, and the Sea.
W E come now, fays the Philoiophier,
to the confideration of things with which we are more intimately acquainted, but which are not, on that account, the lefs wonderful. How was that Mountain lifted up to the fky? How came this cryftal Spriog to bubble on its lofty brow, or that large River to flow from its maffy fidec But above all, how came this Mighty body of water, the Sea, fo colleaed together ? and why and how was it impreg-nated with falt, fecing the fifth and other animals taken out of it are perfe8ly frefh ? Thefe are ueftions not to be anfwered, evenfi by the Sages in Science. Here the Philofopher, at the end of his judgment, and loft in admiration, can only fay with the Plalmift, They that go down into the fea, and occupy their bufinefs in the great waters, thefe men fee the greatness "of God, and his wonders in the deep."Wonderful are thy works, O Lord; in "judgment haft thou made them all !"The earth is full of thy greatnefs 1"
H It

14 Of AMozntains, Spig,&c
It is'the bufinefs of Philofophy, however, to eniquire into thefe thing thoughthi our enquiries are-1fometimes vain. 'We V i hall therefore, in this Le~ffure, give the
beft account we can of Mountains,
Springs, Rivers, and the Sea.
'The antients fuppofedf that Mountains
were originally occeioned by the Deluge ; before which time they imagined the earth wvas, a perfea level : and a certain Abbot was taken into cuftody and punilbied for afferting that the earth was round; 6bough there is :fo great a neceffity for its being ito, that, according to the properpes with -which the Alinighty has endoted tbe fub*lances that corupofe the world, it could 21ot conveniently fubfift i n any other fom; for, not to mention the formation of r'i:VCrs,,vhich are generally occafioned by the mifts that fall on the mountains ; I f th e e4 arth was a regular plain, inftcad of that
beautifuL variety of hill and valleys, of *erdant forefis and refrefhing ftreams, wvhlch at prefent delight our fenfes, a dnWsnal fea would cover the whole face of the globe.; and -at beft it would Le only the
habitation of fifhes.
I Proteft, fays Lady Caroline, I think
youcarry this -argumnent tot) far, 4fLIL foemi to queftiout x~he power of the Creatcr.-hoW

Of 2MountaiZns, S rings, &c 75
How can you tell that the earth and water thus difpofed would have that effect ?From daily experience, Madam; fays the Philofopher. Throw this flone into the moat, and you will fee it fink; or this clot of dirt, and it will fall to the bottom. But, fays lhe, this is not always the cafe; for when I water my flowers, the water fi ks into the ground and difappears.-That is because there is abundantly more earth thanwater, Madam, fays he; and the earth being porous, or hollow, the water runs into the cavities, and fills them; but was you to continue pouring out of the waterpot till all tifefe crevices were full, you would find the water flow at top, and the garden-motid, or earth, would remain at the bottom; for if you take a pint pot of earth, and another of water, and mix them ever fo well together, the earth will in a little time fubfide or fall to the bottom, and the water will be feen at the top. This is to me a demonfiration, Madam; and it is fo far from calling in queftion-the wifdom of God, that it is vindicating his wifdom in the works of Creation. So that you may perceive from hence, as well as from the motion of the heavenly bodies, that the earth is round, and that the Antients were in an error.
H 2- And

7& Of Afountains, Srings, &c.
And with regard to Mountains, though the Deluge might throw up many, and much alter the face of theearth, yet from the great ufe mountains are of in colle&ing the waters of the atmnofphere into fprings and rivers, it is reafonable to fuppole there were mountains even in the firft age of the world.
If I am not miftaken, fays Lady Twilight, it has been fuppofed, and by men of learning, that this irregularity of the earth's furface was occafioned by fame Comet's firiking against it: and this opinion, I know, put Lady Luey and many others in great pain when the late Comet was expe&d. What fay you to this, young Gentleman ?
I am unable to anfwer for all the extravagant conceits and ridiculous follies of the human race, Madam, fays he; add your Ladyfhip might as well expe& me to give a reafon for the poor foldier's prophefying an earthquake fome time ago, and of the terrors of the people on that occafion, as to account for this. That the Earth has undergone amazing changes fince its firft formation, is, I think, evident from the contents of fome mountains, even in our own country; in which we find not only petrifafions in abundance, but the fhells of

Of mountains, Springs, s'c. 77 of fea-fifh, and even the bones of animals, that were never inhabitants of this climate. At Reading, in Berkfhire, which is above forty miles from the tea, there is a firatumn of oyfter fliells, which appear like real oyfters, and are fpread through a hill of confiderable extent; they lie upon a chalky rock in a bed of fand, much refembling that of the fea; and the upper part of the hill which is a loamy foil, is thirty or forty feet perpendicular above them : and at Burton near Petworth, in Suffex, was dug out of a pit, the bones or skeleton of an elephant. Numberlefs curiofities of this kind have been discovered here (fome of which I hall take particular notice of in my next courfe of Leaures); but I think there are few but what may be accounted for from the eff&s of the deluge, earthquakes, and fubterraneous fires. Earthquakes at the bottom of the f a, for infiance, have fomentimes thrown up mountains or little iflarids, with the fith upon them, which have been covered by the fandy or loofe earth giving way, and falling over them. It is not long fince anm ifland was raised in this manner, in the,Archipelago, of ten miles circumference, the hills of which abound with oyfiers not vet petrified, and which are much larger H thak

fMOuntains,' SjI/zrngS, &C.,
tha tliofe taken on the coaift ; whence we rnav ,concl~ude, that they were thrown up frona then deepeftfart of the fea. Sea-fifh haive been alfo found in, other mountains; fom 1t cf which have been petrified. while other;, have been found with the flefh only browned'or muumied.
And fromn the amrazingc quantity of fire contained. in the ececth, and of the fuhterranean air rarefied thereby, great alteraitionS Inuft have been made in its liurfac e in the courfe of f,- m-any years.
Very well, Iaiys Lady Caroline; aknd 10( you are going to tnjrn th e earth into ai hotbed, and I f'uppofeU, w .ho are itsina bitants, are by and lby to be comnplimentedwith the, title of muffhroom-s and cucum)bers, or perhaps pumpkins. This is n philofophy, indeed. Have patience, my, dear, fi'ys the Marchionet's.-Paticnr Ma'am,' returned Lady Caroline, wihy i hope Your Ladyfh-ip would not have mne believe that we have a furnace of fire- W der us,?-I do-not know, Mvadam, whether it he immediately,,unider us or not, replied the little Philofopher ;'but that therear numbers of thefe furnaces in the earth IS beyond dif-Pute, and is evidently proved. hy the oreat number ot burning mountains,
Whlare continually fending upt flames,

Of Mountains, Springs, &c. 79 attended with large ftones and metallic fubflances. I am forry his Grace of Galaxy is gone, Madam; for h*would have fet you right in this particular, which, pardon me, I hall not attempt, fince I find my veracity fo miruch queftioned.-The company all laughed at the Philofopher in a pet; but the Marchionefs took up the mrnitter, and foon put an end to the dispute. She blamed Lady Caroline for offering to decide upon a point which flhe did not underitand; and then turning to the young gentleman, told him, that patience ought to be a Frincipal ingredient in the characer of a philofopher. Upon which Lady Caroline and he compofed their difference with a mutual finile, and after asking the Marchionefs pardon for betraying too much warmth, even in the caufe of truth, he told Lady Caroline, the should have fbme account of thefe mountains from the beft authority; when, taking a book out of his pocket, he read as follows:
The mofR famous of thefe mountains is Etna in Sicily, whofe eruptions of Eame and fmoke are difcovered at a great diftance, by thofc that fail on the Mediterranean, even as far as the harbour of Malta, which is forty German miles from the fhore of Sicily. Though fire and fInmcke are contualty

80 Of Mountains, Sbrings, &c. tinually vomitted up by it, yet at fome particular times it rages with greater violence. In the year 1536 it fhook all Sicily, from the firYi to the twelfth of May; after that, there was heard a moft horrible bellowing and cracking, as if great guns had been fired; there were a great many houfes overthrown throughout xhe whole ifland. When this form had continued about I i days, the ground opened in feveral places, and dreadful gapings appeared here and there, from which iffued forth fire and flame with great violence, which in four days confused and burnt up every thing that was within five leagues of etna. A little after, the funnel, which is on the top of the mountain, disgorged a great quantity of hot embers and afhes for three whole days together, which were not only difperfed throughout the whole ifland, but alfo carried beyond fea to Italy; and feveral fhips that were failing to Venice, at two hundred leagues diflance, fuffered damrnage. Facellus hath given us an hiftorical account of the eruptions of this mountain ; and fays, that the bottom of it is one hundred leagues in circuit.
Hecla, a mountain in Iceland, rages fometimes with as great violence as Ttna, and cut1 out great ltones. The hprifoned fire

Of Mountains, Sflrings, &c. 8I
fire often, by want of vent, caufes horrible founds, like lamentations and howling; which make fome credulous people think it the place of Hell, where-the fouls of the wicked are tormented.
Vefuvius in Campania, rnot far from the town of Naples, though it be planted with moft fruitful vines, and at other times yieldeth the beft Mufecadel wines, yet it is very often annoyed with violent eruptions. Dion Callffius relates, that in the reign of Vefpafian, there was fuch a dreadful eruption of impetuous flames, that great quantities of afhes and fulphureous fmoke were not only carried to Rome by the wind, but alfo beyond the Mediterranean, into Africa, and even into Egypt. Moreover, birds were fuffocated, in the air, and fell down dead upon the ground : and fithes perifhed in the neighbouring waters, which were made hot and infe&ed by it. There happened another eruption in Martial's time, which he elegantly deferibes in one of his epigrams, anfid laments the fad change of the mountain, which he faw firft in its verdure, and immediately after black; with aflies and embers. When the burning ceafed, the rain and dew watered the furface of the mountain, and made thefe.fulphiureQous athes and embers fruitful, fo that they

St Of fountaim, Springs,- &e.
they produced a large increase of excellent wine; but when the mountain began to burn again, and to diforge fire and fmnoke afreAi (which foinmeinmes happened within a few years) then were the neighboring fields burnt up, and the, highways made dangerous to travellers.
"A mountain in Java, not far from the town of Panacura, in the year 1586, was shattered to pieces by a violent eruption of glowing fulphur (though it had never burnt before); whereby (as it was reported) ten thoufand people periflhed in the under-land fields. It threw up large flones, and caft them as far as Panacura; and contirnued for three days to throw out fo much blac fke, mixed with flames and hot mbers, that it darkened the face of the fun, and made the day appear as dark as the night."
There are a great number of other mountains, or (as your Ladyfhip is pleafed to call them) furnaces in the known world to enumerate them would be too tedious to my auditors.
We come now to the confideration of Springs; which are occafioned principally, we may fuppofe, by the water exhaled from the fea, rivers, lakes, and marfthy places; and, forming clouda, are difperfed by

Of Mountain s, Spgs, &c. 83
by the winds. There clouds, when they are fo colleied together as to become too heavy to be fupported bythe aiir, fal downi in rain to water the herbs and plants; but thofe that are lighter, being driven aioft inII the-air, daih against the mountains, and to them give up their contents in fiiall particles; whence entering the crevices, they defcend till they meet together, and form fprings: and this is the reafon why we have fuch plenty of fprings in mountainous countries, and few or none in thofe that are flat. And you may obferve that it frequently rains in hilly countries, when it is clear and fine in the vallies beneath; for the air in the vallies is denfe enou to fupport the clouds, and keeps them pended; but being driven up among me tains; where, in confequenceof theirheight, the air is fo much lighter, they descend in mifts or fuch finall drops of rain that will not run off, as is the cafe in a heavy rain, but fink into the crevices of the earth, in the manner already mentioned. Now, that a great part of this water is exhaled from the fea, may be known by the extraordirary rains and great dews which fall upon iflands that are furrounded by the fey; but fome fprings, it is reafonable to fuppofe, have their fours from the ocean, fince, thofe

4 Of M.Aountains, Springs, &c.
thofe which we meet with near the fea are generally fomewhat falt or brackilbh.
Thefe fprings, thus formed by the mifls on mountains, and the rain meeting together, form little rivulets or brooks; and thofe again uniting, compofe large rivers, which empty themselves into the fea: and in this manner the water, exhaled from the fea by the fun, is returned to it again; for Providence has eftablifhed fuch wife laws or regulations for the world, that no part of the element can be annihilated. But the very large rivers muft have fome other fource befides the fprings formed by the. mifts, dews, and rains, fince thefe feem infufficient to fupport their prodigious difharge; it is therefore no improbable conure, to fuppofe that they have fomIe communication with the fea, and that the falt water is purified and rendered fweet by pafling through the fand, gravel, and crevices of the earth.
Lakes are colle&ftions of water contained in the cavities of the furface of the arth ; fome of which are faid to be ftagnant, and made up of the waifte water that flows, after rain or fn6w, from the adjacent countries; and thefe muft be unwholefor(-. Other lakes are fupplied by rivers, theettents of which they receive and cn

-Onder ground, to form other i-)r*
ZD i ings and
rivers : others, al-gain, are fed by fprlngs
-which arife in the Like itic1f; and Ionic (,is that of Hacylem, and other fitit have a communication, it is foppofed, ill the fealwhence they r,ccIve th ,Ir watl-1, and afterwards (11.CiMi-"C UICIII hy fUbLcrrapean fircalil S.
The fea is, a 'great co'!,I-,'I ion of wza(r Ill
the dcep allies of the C'Irth' ; I fay, )n deep Valli es ; for if there %vere not i)ro,11gious.cavities in the earth to contal 1 11 11 "1 S' ainazing quintiry of water, thus coflc fcd tolyetlier, tlic- Whole surface of the g1lo'would bc o cd ; for the xatt r bc'
lighter 1han the carin, would b ihove tli c arth, as the aP Is bovE the water.
Now yoki fpca!, ot the I-ea, fays the -Niar chionefs, I lfh youwould tt 1, 1 iric ,% hy tlic' fea-water is zdkva%'s f-At. 'Madarn, replied he, I Wifli 1 co"Ild ; but it -is I)cvond the TeaCh of Ill)! jdIi!0f0j)LY, UUd lnd ed I beIiQve of any 11 )Iloloph,:r whatevcr- althoug-W fonic _that the rivers in their puffaoc extiaLll the falts froin the earth and convey them to the fea.
I havt often thought, fromll-e prodigiots quantity of falt' dIlributed in th c earth and water, that it muft have quallnes which wcknow not of, and anfwcr

purposes in -the feale- of being, with AIlI we are drnacquainted.
The unofi. reniatkable quality in thRe fea2 next to its faltnel is that -notion or rifinl.2 and falling of the water, which wve call tides, an 'd which is occafioned by the attraffion of the moon ; which I mentioned in my fecond Le~ture (page 26) ; for that part of the water in the great ocean which is nearell the moon, being fltongly aittraaced, is raifd higher than the reft; aid the, part oppofite to it, on the contrary lide-, being leaft attraaed, is alfo higher than t Iit rfeft; and thbefe two oppofitte fiders of the furface of the water, in the great ocean, following the motion of the mooli1 from c2ft< to Wet and firiking againfi, thf, large coaff of the continent, fromn thence reb~oun. back again. and fo make floods and ebb I-f in narrow feas and rivers, at a diflancc from the gteat ocean. This alfo accourits for the periodical times of the tides, arid for their confiantly following the courfe of the inoqn,