1S4 
GAL 
ence, by treating, in a clear and geometrical manner, the 
dodtrine of motion, which has been jiiftly called the Key 
of Nature. The rational part of mechanics had been fo 
much neglected, that fcarcely any improvement was 
made in it for alinofl two thoufand years; but Galileo 
has gi'ven us fully the theory of equable motions, and of 
fuch as are uniformly accelerated or retarded, and of thefe 
two compounded together. He, firft, demonftrated, that 
the fpaces defcribed by heavy bodies from the beginning 
of their defcent are as the fquares of the times ; and that 
a body, projefted in any diredtion that is not perpendicu¬ 
lar to the horizon, defcribes a parabola. Thefe were the 
beginnings of the do6lrine of the motion of heavy bodies, 
which has been fince carried to fo great a height by fir 
I.'aac Newton. In geometry, he invented the cycloid, 
or trochoid; though the properties of it were afterwards 
chiefly demonftrated by his pupil Torricelli. He invent¬ 
ed the fimple pendulum, and made ufe of it in his altrono. 
mical experiments : he liad alfo thoughts of applying it 
to clocks ; but did not execute that defign. The glory 
of that invention was referved for his fon Vincenzo, who 
made the experiment at Venice in 1649 ; and Huygens af¬ 
terwards carried the inveniion to perfection. Of Gali¬ 
leo’s invention alfo was the machine with which the Ve¬ 
netians render their Laguna fluid and navigable. He 
alfo difcovered the gravity of the air, and endeavoured 
to compare it with that of water; and opened feveral 
other enquiries in natural philofophy. He was not 
efieemed and followed by philofophers only, but was 
honoured by perfons of the greateft diftiniftion of all na¬ 
tions. Galileo had fcholars worthy of fo great a mafler, 
by whom, the gravitation of the atmofphere was ellablilh- 
ed fully, and its varying prelTure accurately and conveni¬ 
ently ineafured, by the column of quickfilver ot equal 
weigl'it fufijined by it in the barometrical tube. The 
elafiicity of the air, by which it perpetually endeavours 
to ex pand itfelf, and, while it admits of condenfation, re¬ 
fills in proportion to its denlity, was a phenomenon of a 
new kind, (the common fluids having no fuch property,) 
and of the utmolf importance to philofop.hy. Thefe prin¬ 
ciples opened a vafl field,of new and .ufetul knowledge, 
and explained a great variety of phenomena, which had 
been accounied for in an abfvird manner before that time. 
It feemed as if the air, the fluid in which men lived from 
the beginning, had been then firft difcovered. Philofo- 
phers were every where bufily enquiring into the various 
properties and their eft'effs ; and valuable difcoveries re¬ 
warded their induftry. Of the great number who diftin- 
guilhed themfelves on this occalion, we cannot but men¬ 
tion Torricelli and Viviani in Italy, Pafcal in France, 
Otto Guerick in Germany, and Boyle in England. Ga¬ 
lileo wrote a number of treatifes, of which the principal, 
publiflied during his life-time, befides his Mechanics, 
Balance, and Dialogues, already mentioned, were : 
1. The Operations of the Compafs, geometrical and mi¬ 
litary, loo"). 2. A Difcourfe addrelied to the moft ferene 
Cofmo 11 . Grand-duke of Tufcany, concerning the 
Swimming of Bodies upon, and their Submerfion in. 
Water, 1612. 3. Nuncius Sidcrevs, 1610, of which, 4. A 
Continuation, or An ElTay on the liiftory of Galileo’s laft 
Obfervations on Saturn, Mars, Venus, and tlie Sun, &c. 
was afterwards colleiSled from letters between G li'_eo and 
his correfimndents. 5. A Letter concerning the irepi- 
dation of the Moon, inferibed to Alphonfo Antonini, 
with Antonini’s Anfwer, 1638. 6. A Difcourfe of the 
folar Spots, &c. with Prediftions and Ephemerides of the 
Medicean Planets, 1613. 7. The famous Italian piece 
entitled, li Sa^giatore, written in defence of Guiducci’s 
Difcourfe on Comets, 1623. 8. A Letter to Prince Leo- 
pold of Tuicany, examining the fiftieth Chapter ofLice- 
Lcthe.ofpharos. 9. A Letter to Chriftopher Greinber- 
gerus, concerning tlie Montuofity of the Moon, i6ii. 
iQ. M tihematical Difeourfes and Demonftrations concern 
ing two new Sciences, relating to Mechanics amTlocal 
.Motions, together with an Appendix concerning the 
GAL 
Centre of Gravity lit fome Solids, 1638, &c. The pre¬ 
ceding articles, together with fome other treatifes writ¬ 
ten either by Galileo, or by fome of his difciples in de¬ 
fence of his dodfrines and obfervations, were colledled 
and publithed by Menolefli, in 1656, under the title of 
VO pare de Galileo Galilei Lynceo, nobile Fiorentino, Sec. in 2 
vols. quarto. Several of thefe pieces were tranflated in¬ 
to Englifh, and publiftied by Thomas Salilbury, in liis 
M ithematical Colledlions, in 2 vols. folio. A volume 
alfo of his Letters to feveral learned men, and folutions 
of a variety of problems, was publiftied at Bologna, in 
quarto. His laft difciple, Vincenzo Viviani, who proved 
a very eminent matliematician, methodifed a piece of his 
mafter’s, and publiftied it under.the title of Qiiinto Libro 
de gli Elementi d’Euclide, See. 1674, quarto; and he alfo 
publiftied fome other pieces of Galileo, including ex. 
tradts from his Letters to a learned Frenchman, in which 
the author gives an account of the works which he in¬ 
tended to have publiftied, and an extradt.of a letter to 
John Cafnillo, a mathematician of Naples, concerning 
the angle of contaef. Many other of Galileo’s writings 
were unfortunately loft: to the world, ovdng to the fuper- 
ftition of one of .liife ignorant nephews ; who, conftdering 
that his uncle died a prifoner of the holy office, though 
permitted to refidc in his own houfe, fufpedted that his 
papers might contain dangerous herefies, and therefore 
committed them totlie flames. Sir John Finch, in a let¬ 
ter to Thomas Salifbmy, attributes the deftriidtion of 
Galileo’s MSS. to his widow’s devotion, and the fanati- 
tifm of her confeflTor ; but the beft authorities maintain 
that Galileo was. never married. His fon Vincenzo Galilei, 
who honourably I'upported his father’s reputation, by firft 
applying his invention of the pendulum to clock-work, 
was of iilegiiiiiiiite birth. 
Vin'cekzo G.vi.iLri, the father of Galileo, w'as a. man 
of letters', nor unlkilled in the iiiathematics, and'particu- 
larly converf.int in the fcience of muiic. He wrote fome 
elaborate works, of which the moft efteemed confift of 
five dialogues concerning harmony, and its meafures and 
tones, with rules for compofing, and other prtidfical parts 
of ancient and modern mulic. 'Fhe firft bookjs entitled, 
Foroinino, 0 Dialogo, nel quale fi contengono le vcrc & necejfarie 
Regale di intavolarc la Mujica nelLiilto, 1 569, folio. He like- 
vvite wrote a defence of it, entitled, Dialogo della Mujica 
antica S 3 modcnia in fuo Difjo contra jojeffo Zarlino, 1602, 
folio. 
GALI'NA POINT, n cape of the ifland of Jamaica, on 
the north coaft. I,at. 18. 26 . N. Ion. 76.41. W. Greenwich, 
GALIN A'GO,y [dim. of acock.] The wood¬ 
cock. An eminence witliin the proftrate gland is called 
caput gallinaginis, from its fancied refemblaiice to a wood¬ 
cock’s head. 
GAL'INGEN, a town of Pruflia, in the province of 
Natangen : four miles fotith of Bartenfteiii. 
G.‘\L'!NHAS, a river of Africa, which rifes in fhe 
country of Hondo, and runs into the Atlantic : eleven 
leagues from Scherbro. The Portuguefe call it Magu~ 
albari. 
GALINSO'GEA, y in botany, a genus of the clafs 
fyngenelia, order polygemia fiiperflua. The generic cha¬ 
racters are—Receptacle chatty ; down many-leaved, chaf¬ 
fy ; calyx imbricate. 
Species, i. Galinfogea parviflora: leaves ovate, trip¬ 
ly nerved, ferrate ; peduncles one or two flowered. Inha¬ 
bits Peru. 
2. Galinfogea trilobata : leaves oblong-lanceolate, 
toothed, triply nerved; lower-ones halbert-ffiaped and 
three-lobed ; flowers fomewhat corymbed. Inhabits 
Peru. 
GALINTHIA'DI A, a feftival at Thebes, in honour 
of Galinthin.s, a daughter of Preetus. It was celebrated 
before the feftival of Hercules, by whofe orders it was firft 
inftituted. 
GALIPA'GOS, a clufier of uninhabited iftands in the 
South Sea, on botii lides the equator, not far from tlic 
' coaft 
