160 CHRONOMETRY. 



detached escapemenf, which, if it were really such, would 

 of course be the first model of that idea ever communi- 

 cated to the world, knd would consequently degrade Le 

 Roy from' the rank of an inventor to that of a mere 

 . copyist or imitator. The real state of the case, however, 



is as follows : — The Academy of Sciences in 1748 received 

 the escapement of Le Roy as new, though Thiout's book 

 was published only a few years before ; and no opposition 

 was made to this declaration by the author, (whom we 

 believe to have been then alive,) or by any of his friends 

 HJs contcmpo- and successors. One of the committee who examined 

 t^bouchrV *^'^^ invention was Mr. le Ca^nus, a good judge of watch- 

 making, who, as such, came, afterwards, with Mr. Ber- 

 ^ • thd^d, to this coitntry, by order of the French Govern- 



menf^ in order to witness the disclosure of the principle 

 of Mr. Harrison's time-keeper; and the same Mr. le Ca- 

 mus, who first mentioned that Dutertre the elder had . 

 conceived the idea of a detached escapement, according to 

 a construction which was preserved in his family, never > 

 . said any thing respecting the invention of Thiout, al- 



though that inventid* was described in a work generally 

 k|jown. Nay, the Academy of Sciences continued so 

 miserably blind, that when, some years after, Mr. Pla- 

 tier. ^submitted to^that body a new detent escapement, 

 their committee declared, that P. le Roy was the first who 

 had thought of this sort of escapement*. The same 

 — nor subsc- igporaitce, or wilful error, has, since that time, attended 

 quent writers. ^^^ ^^^^ ^^^ philosophers who have candidly endeavoured 

 to investigate these matters, but also the critics ajid rivals 

 who may liave maliciously searched for circumstances 

 likely 4;o humiliate the pride of the different competitors 

 who have pretended to the credit of originality in the 

 construction^of the free escapement. This we cannot 

 but ob&eryc seems an extraordinary case. The truth 

 Mr.'^cid has howevefis, as may be easily guessed from the preceding 

 capc^tnt^from statement, that the representation of the escapement, as 

 that published published by »Mr. Reid, is totally different ftom the \ 

 by Thiout. 



, * * " M. le Roy I'aine est le premier qui ait pense a cette sorte 



# « d'cchappemcnt " Observations sur la Physique, Sec. par 



M. r ABbc Rozier, T. III. Par t I. Juin 1774. 



figure 



