HOROLOGY. 



117 



l)-t ptndu- 



'. .. 



being let go. continue* to vibrate for 

 ble time, and with the utmort regularity. Many 

 things in domestic life were bung up or suspended 

 by string*, and were every clay seen or observed ; 

 yet what a long time elap*ed before any thing of thi< 

 kind was mr thought of, or applied to regulate 

 the motion of a dock ! It is said that Galileo took 

 hi* idea of a pendulum from the motion of a lamp, 

 " from the roof or ceiling of a church, which 

 been accidentally set a vibrating. He used the 

 simple pendulum in his astronomical observation*, 

 long before it was applied to a clock. Some of the 

 earlier astronomers, as well as Galileo, oaed a com- 

 mon string and ball, which they nude to vibrate a 

 little while, daring the time of an observation of 

 any of the heavenly bodies. Yet even these aatro- 

 nomen did not think of it* application to clocks. Some 

 watch-finishers, when their watch it finished, for waat 

 of a pendulum dock, regulate it by mean, of a ball 

 and string, which will answer very well, by taking 50 

 vibration* of a pendulum'* length for seconds, 

 same time that the wheel ought to raakeone revolution. 

 A* gravitation i ; the principle on which the pendu- 

 lum is founded, it cannot properly be considered a* 

 sn invention, as some have called it* whatever name 

 may be given to it when applied to regulate the mo- 

 tion of a dock. The pendulum having before this been 

 Ions? known hi ha simple state, ana used a* a sort 

 of lisas inissmrr. it was no wonder that the idea of 

 applying it to a dock, was entertained by several per- 

 tons nearly about the same period. The movement of 

 the old balance docks was not adopted for the application 

 of the pendulum, so a* to give moOon tu it : thr wheel* 

 in it were all flat one* except the CIUWB wheel, and no 

 : at this time was known at that of the 

 :e ; so that, without conaidarabls 



be applied to thb rsnstiortiiiii of a dock 

 The pocket watch had boon 

 before this, and the construction of its 

 had a contrite wheel in it. woold naturally land them 

 to that of one which would adapt itself to the motion 

 of a pendulum, as by mean* of the contrate wheel the 

 crown whorl could be msd* to stand in a vertical 

 position ; where**, in the old *T 1 irT'* dock*, the poai- 

 t*oo was horizontal. Gattlao seem* early to have dis- 

 covered the properties of the psndahim, and the in- 

 MIBB witli ffsftn MIGCCM by I iwv- 

 The son' of Galileo spphed the penmslam to 

 "fv** a dock at^ Venice in the year 1649; but to what sort 

 of a movement wo cannot pretend to say, Bswsjrh we 





he had not sskansil 

 Jtaapy asatHiiinJ as 



f the ansftli 

 e, another eat 



have stianilnl his trial*, that 



vftW ODsMaTVVF WO^W tDOVCtnCVIt 



the most proper for it. We know* that 



made ose of this sort of movement, as the 



fit to be regakted by the motion of the 



whieh ha had also applied. Of late, 



date for the spall foil nil of the pendulum to a clock 



has been bnaght forward by such taspertebl 



ty. that lea\n Utie or no rtii t.. .!..ul,t ..(' n 



ncity. Mr Gnrruon inform. , that a clock 



r Richard Harris of LonaVm, fnr the church 

 * M Paul'.. ( ovent (rtnlen, ami U.A! thi. . I,M fc i,.,., , 

 panJalum to it." 



It appear*, from unquestionable evidence, that Galileov 

 to the Grand Duke of Tusoany. fir* 

 properties of the pendulum. a*ed it in 



hi* astronomical observations, and wrote a tract ex- 

 plaiiung the principles ot" it. This tract was translated 

 from the Italian into French at Paris, printed in 1639 

 in a duodecimo volume, ami sold by Pierre Kicolet. 

 He intended to apply it to a dock, but this he never 

 put into execution. Father Alexander says, " that they 

 bad nothing better than the balance clocks in France 

 until the year 1660." 



The application of the pendulum to a clock, and of 

 the spiral form of a pendulum spring to the balance of 

 a watch, were the greatest improvements that could 

 possibly bare been made in the machinery of tirac- 

 mMSBiing, and they both happened to take place near- 

 ly about the same period. 



Notwithstanding the application of the pendulum, Huygtn='- 

 aml the ingenious contrivance of cycloidal cheek* by cluck. 

 Hurgens, in order to make the long and short vibrm- * Te 

 tiom be performed in nearly as equal time a* possible, 

 yet the clock did not keep 'time with that correctness 

 which was expected : This arose from the great extent 

 of the arc of vibration, the. lightness of the pendulum 

 hich the clock had ove 



ball, the great tfsasi*ii w 



and the bad elects 



over the 

 uced by the cycloi- 



?> A 



prc 



ilal checks, whieh, however excellent in theory, were 

 never found useful in practice. See Fig. 4. where 

 a front view of the cycloidal cheek* is represent- 

 ed in Fig. A. Thi* led artists and amateurs of the 

 profession to think of farther means of improvement . 

 accordingly, about the year 1680, a clock was made 

 ment, a clock-maker in London, having 

 in place of the crown-wheel and verge 'scapsment, 

 a 'scapemrnt which was nearly the same a* the com- 

 mon recoiling 'atapement of the present day. The 

 wing-wheel S W was flat, having a sort of ratchet or 

 saw-like teeth; and the pallets P, P had a remote rasem- 

 bknceto the head of an anchor, by which it acquired at 

 that time the name of the aH-Aor'*cp<m(fn/. Sea Fig. 5. Anf hor 

 The ball of taw pendulum was made much heavier than * V m:t*> 

 what had formerly been adopted, the arc of vibration PI.ATX 

 much shorter, and the motive force much leu. From the CCC. 

 asjsj|lan> Moa-hiffisg of the clock, this was found to be ri 

 a great iaspravonunt, and hence thi* 'acapement was af- 

 terwards generally practised. It passed into Holland 

 and Germany, and was hardly known in France until 

 the year 1695. See Hiftoire dt la Mr surf d Tempt, 

 torn. L p. 100. 



>e time when thi. clock of Clement'* appeared. 

 Mr i I *e claimed the invention of >t a. h,-. ,; 

 firmed, that alter the great fire of London, in 1666, 

 be had shewn to the Boyal Society a clock with thi 

 caussaMit. " Considoring," says Sully, in hi-> 

 lluttivr dri Hecmpprmtnt, " the genius, ami the great 

 nmnber of fine diMoverie* of thi* ekcdlent man, I are 

 no room to doubt that he wa* the nnt invent. .r <>i it ' 

 The prtuhtlmn with this 'seapenwat had received the 

 am* of the rOjaW oraaWmt. 



TboaVaW.OMl scapernont of Graham'* next succeed- Gnham'i 

 ed, which wa* invented some time alter the boajuuunc of dml-bcat 



we laghtssmh century, and has continued to be that **?ai>tr.t. 

 which is generally used in regontors, or astMaomical 

 docks, with a very few exception*. Seel uttenpig. . 



orfitteenyeanafterward*,itcainetobeknn MI I ranee, 

 and wa* adopted there aiso a* the best for dock* in- 

 tended to m assort time very accurately. Leoaute, a l^paau'i 

 very mgenino* watchmaker in Pari*. produced, about mpwre. 

 the year 1753, or sometime before it, a 'scapoment "*" "I** 

 foundeil on that of GratunV* (load-beat one See 1 ig. 7. ' fig T 

 In Lepaute's, tberestof the teeth on Ute pslkt* was al. 



