^ MR. RBID ON TIME-KEEPING MACHINES, 



fteel wires put through the ball, paffing parallel to each other, 

 and each put a little to one fide of (he centre, through which 

 pendulum r^s are ufually made to pafs, and when the rod is 

 wood, it neceflariiy takes away much of the matter from the 

 centre of the ball. 



A pendulum of this fort of mine, and which has a degree 

 of compenfation in it, I made to a clock, which my brother 

 got, and which he has at his houfe. No. 31, Rofamon Street, 

 Glerkenvvell. 

 Theexpenmenc J mentioned this mode of putting clocks mechanically on 

 ^Itthes^Scc, ^^^^' ^^ "^y '"g®"'0"^ friend, Mr. Pennington, who has fince 

 very happily applied the fame fuccefsfully in his practice to 

 watches, &c. 

 pcni^ulum for I fee you have mentioned in your Journal of July laf!", the 

 ftr1k'iDg"palt of application of a pendulum to regulate the ftriking part of clocks, 

 docks} noc new. from the Society for encouraging Arts, &c. having given a 

 t ^ premium for it to Mr. MafTy. 



This is riot a new thing. Mr. Berlhoud mentions it as his 



invention, and you will lee a drawing, and the defcription of 



it, in his EJfaifur I'Horlogcriet publiflied in 1763. Julien Le 



Roy, in my humble opinion, is certainly intitled to the merit 



of it, as it appears to me, that Berthoud has taken the idea of 



it from Le Roy*s method of regulating the ftriking train of his 



repeating watches, which he invented, and applied to them 



about the year 1754. 



The crank There wa-s a premium given alfo in 1799, by the honour- 



fc<»i>cnient, not able fociety above mentioned, for a new 'fcapement by Mr. 



* Goodrich*; now this M'capement was made prior to the year 



1740, and ihvented by the Abb^ Soumille ; and another nearly 

 of the fame fort was made at Rome before that period, as may 

 be feen in the colIe<5tion publilhed by Thiout, in the year 



1741. Surely nobody would think of adopting fuch a 'fcape- 

 ment as this, whofe principle feems to be that of depriving 

 the penduluni of the mofl valuable property it pofleflTes, viz, 

 that of having the liberty to operate freely under the influence 



and bad* of gravitation. Tliis *fcapement keeping the pendulum, z% 



it were in leading firings. 



I am furprifed that none of the members of this honour- 

 able and ufeful fociety, fliould not have known, that thefe 



t See Philof. Journal, quarto feries, III. 342, 416. It is a 

 crank. — N. 



things 



