IIOROLOC; v. 



an rf 

 sBiin 

 "> * 





the h'mitt of the banking, the steel crank of the other 

 confining the extent of banking. There is no doubt 

 greater risk of breaking than in the cased one 

 this might be considerably lessened were some atten- 

 tion paid to make the notch which frees the bottom 

 of the wheel, as has been proposed in the case of the 

 steel cylinder, no longer than is necessary. It would be 

 desirable to have the cy limier formed by the strata of the 

 sapphire or ruby, being placed in a vertical position in- 

 stead of a horuontal one. This is surely attainable, when 

 we know that diamond splitters can distinguish the strata 

 or layers of the diamond, a stone which may be suppo- 

 sed more compact than either the ruby or sapphire. We 

 have seen a cylinder, wholly- of stone, hi a watch be- 

 longing to a n't ntleiaen, who was wearing it when be- 

 tween " so years of age; be ned frequently to 

 let it fall without any accident happening to the 

 cylinder. Three unall griffs or cocks placed on the po- 

 tence plate, so as to allow the balance edge to come into 

 notches fined for it. and having sufficient freedom, 

 would prevent either the cylinder or the cock pivot from 

 breaking. A little practice should make the stone cylin- 

 der easier, and perhaps cheaper s*ade, than the cased i .ne ; 

 at all events, even on equal terms, it ought to be the 

 preferable of the two. Frosn what has already been said, 

 it appears that the weight and diameter < t the luUnce 

 are matter* not merely arbmary ; for if the motive 

 force is too great for that of the fore* of the balance, the 

 watch will go fast when in the laying or horisotital po- 

 sition, and slow when in the vertical or hanging position: 

 By ditahusJung either the motive force, or making 

 the balance heavier, the watch may be made to go the 

 same in both position*. The properties of the pendu- 

 hun spring may conduct a little to this. It is in MSB* 

 for a pocket watch to have the 



short cylinder of two-tenths of an inch in diameter ; 

 the upper end of the cylinder was cut down nearly 

 one-half of the diameter, and (lunched to the lower end 

 and opposite side, rounded off from the circular p.-.i-t of 

 the base left at top, to the lower end of the flam-h, re- 

 sembling something like a cone bent over, and \\.-nt- 

 ing a pert of the top. Two flat balance-wheels, having 

 ratchet or crown wheel sort of teeth, were on the same 

 arbor, the teeth of the one being opposite to the mid- 

 die of the spaces of the other ; the distance between 

 these wheels was a little less than the diameter of the 

 cylinder ; the drop of the teeth in scaping falls on what 

 was left of the upper base of the cylinder, (the lower 

 base being taken away in forming the pallet) and near 

 to the edge farmed from the flatten ; here they rested 

 during the time of the vibration of the balance. On the 

 return, the tooth gets on the flanch, and passes over it, 

 during which, giving impulse to the balance, and esca- 

 ping at the lower end, a tooth of the other wheel drop* 

 opposite on the same base of the cylinder, and so on. A 



baW* pi vou and hole* made B*> thai the balance .th 

 to spring, when in a state by itself, end free of any 

 lUBiBMlikellae, with the wheels, should vibrate the 

 same length of time, whether it is in a vertical or 

 horizontal position. We know when it is in the last, 

 that it will continue to vibrate twice the length of time 

 that it will do in the other. We are humbly of opinion 

 that thi* could be come at But who will be at the 

 trouble end eanence to make such jrpeiiiiK'iits a* may 

 Eamahaw's pivot*, with Hat end* and 



\ years ago we used to hollow out the end* 



n\ BHttltt I' \ ' t v 



In the iiHtiiui, between Tampion's having left of 

 hi* trial* in attempting the borisontal 'icsfiment, end 

 Graham's having brought it to a state of perfection, 

 V I joo, A njrtivr OT OtfwvSy heWing dMCovtwd the 

 tut oi pi*rciTi(f bowi in mole?*, op my ruwtl pcvcMNM 

 stone, came to Paris with this an aa a secret ; and not 

 being well received, either by the Duke of Orleans, at 

 that time recent of France, or by the watchmaker*, he 

 repaired to London with it about the year I70O. which 

 wa* at that time a school where the an of horology wa* 

 more cultivated than at Paris. lie wa* llfcsjPMli a 

 member of the Royal Society, and having entered into 

 kind of pottoenhii) with a native of France, who hod 

 been settled in Louden, whose name wa* Deb 

 carried on the baeineas of watch-jewelling. Facio's 

 partner had, at this time, contrived a new 'scapement . it 

 wa* a dead beat one, which was the thing now (ought for. 

 The balance and balance-wheel bole* of it were jewel- 

 led ; the pallet wa* made of diamond, farmed from very 



having this 'scapement, and bearing Debaufre's 

 name, was put for trial into the hands of Sir Isaac New- 

 ton, who, in shewing it to Sully in !?<), gave a very 

 fluttering account of its performance. It attracted Lil- 

 ly's notice very much, but thinking it by no means; 

 well executed, and not being quite satisfied with two 

 wheel*, it was thought that an improvement would IK* 

 made by having- one wheel only and two pallets, wnic-h 

 was part of the scheme of the 'scapement he adopted 

 for his marine time-keeper made in 1721. Considering 

 the genittt which Sully was allowed to possess, this was 



fre's 'sc 



by no mean* an improvement on Debaufre's ' 



Although an Kn*j)i*hsjMa, Solly'i name was unknown 

 to bis countrymen ; and would have remained so, had 

 it not been for the accounts given of him by tle French 

 artists, in whom he excited an emulation, and whom 

 be inspired with a taste to acquire such a pre-eminence 

 in then* profession as had been before unknown to them. 

 Julien le Roy, who was intimately acqnaint 1 with Sully, Account r 

 and Bertboud, are uncommonly lavish of their enrom'i- the lubours 

 unison him. Soon after he had completed hi apprentice- of sully. 

 ship with Mr Ciretton, watchmaker in London, he went **") fir * 

 over into Holland, Germany, and Austria, and attract- I"'.;! 1 "*" 



, , , , * . . niic lime- 



mg the notice of several of the princes and noliihty, he keeper. 

 was much employed by them. Having sren, in the li- 

 brary of Prince Eocene, the Mtmoir -itte- 



my ofSfientttttl'ant, bo eagerly unpnnil thr French 

 order 



language in 



to road them This excited in him 



strong desire to eee Paris, to which he repaired about 

 the year 1713 or 171*. under the patronage, and in the 

 tile of the Dnkeof Areroburg, at whose hotel he lodged, 

 of < He had not been long 



r countryman I jw of Latin-ton, under 

 the authority of the court of Versailles, got him enga- 

 ged to establish a manufactory of clocks and wai 

 In fiineaqsjenea. of this he came twice to London, and 

 having carried away a great number of orkmen at a 

 vast e> pence, and spent much money on tooU and 

 article*, Law began to murmur, and the esta- 

 in two year* or little more fell to the ground. 

 This made him complain bitterly of his had fortune 

 to a friend ; but fortunately a nobleman to whom this waa 

 mentioned, feeling much for the disagreeable situation in 

 which Sully wa* placed, sent him in a present some share* 

 in the pul value 12,000 livres, which enabled 



him, for several yean afterwards, to pursue very *ea- 

 lousry his favourite scheme of making a marine time- 



VOL. XI. PART I. 



fasaUj, or pant, WOT at that 



so late ss I77S. 



* 



