INVENTION OF THE BALANCE SPRING. 



" the same situation, by being left behind in an invention 



<* which had presented itself long before to several artists ; 



" but M. L. R. wants to appropriate it exclusively to 



*' himself; and, on ihe contiavy, I have done homage to 



" M. du Tertre, as to him who had the first proposed it; 



** although, assuredly, I had no knowledge of any 'scapcment 



** of this sort when I proposed mine, executed and in a 



** finished state, to M. Camus. We readily perceive why Diflerent es- 



« M. L. R. is so jealous of this invention : he is persuaded ^^P|j;^^^=^^^]^^ 



" that iC is by the ^scapement that the most part of the 



** trials have miscarried which have been made to discover 



** the longitude by timekeepers, and that the 'scapement, with 



** the detent and free vibrations, is exempt from all faults. 



*' I am very far from thinking on this subject as he does ; but 



" this is not the place to enter into a discussion, which would 



''* lead us too far. I believe, moreover, that we might make 



^' use of, and with equal success, 'scapements of a very difler- 



*' ent nature : and this is not an opinion, it is a fact proved by 



" experience. The marine watch of Mr. Harrison, that of 



** M. L. R., and my clock, have each a 'scapement, which 



" differ essentially from one another, both in their principle 



** and in their action. Moreover, I shall make no hesitation 



" to use the 'scapement with free vibrations, if the experiments^ 



** which 1 propose to repeat, ever prove to me that it is prefer- 



** able to any other ; and in that I will make use of it as my 



" own right, and shall not think or believe myself to have co- 



*' pied, in any manner, neither that of M. L. R. nor that of 



'' M. dii Tertre, for I know not the construction of the 'scape- 



" ment of this last; and those of this kind, which I have con- 



" trivcd, may be seen in my Traite des Horloges Marines^ 



'' differing from the 'scapement of which M. L. R. has given 



*^ us the descripticm of in his Mesiire du Temps en Mer, I 



** will likewise not dispute against the preference which 



*< M. L. R. thinks that his 'scajjeraent ought to have over 



" mine ; it is so natural to love our children even when they 



" are only adopted. 



M. Berthoud, in his Supplement au Traite des HorIogesTimej?ieceso£ 

 Marines, says, that he executed five marine clocks h-ning ^^'''^'^°"*^' 

 the 'scapement with the spring -detent, (detente-ressori:) ^ 

 which were begun in 1708, and completed m 1782. Ih-se 



who 



