56 EXPERIMENTS ON C H RONOM KTER S . 



does It evaporate foon ; I have found it in jewelled, verge, and 

 horizontal watches, in that warm climate, after a period of 

 three years, in a very fluid ftate, and in fufficient quantity. 

 That oil may be eafily procured here by breaking the (hell of 

 the cocoa nut, drying the nut in a very gentle manner, and 

 afterwards expreffing the oil from it, which is yielded in a great 

 quantity; it aifumes a concrete form in a very moderate degree 

 of cold, but how far that may be a good objeftlon againft its 

 ufe in this climate remains to be determined. 

 MuJge's fii-ft I vvill conclude thefe ohfervations, after a few remarks upon 



fbf\van°oroil ^'^"^ flopping of Mr. Mudge's firft watch, while under trial at 

 on the pallets, the Royal Obfervatory ; Mr. Mudge found, after a good deal 

 of pains taken in inveftigating the caufe, that it was for want 

 of oil being put to the pallets (or locking part) of his Tcape- 

 ment : I think this cafe fo parallel to that of Mr. Haley's ma- 

 chines flopping from the fame caufe, that it tends in forae mea- 

 fure to piove the truth of what I have advanced : Mr. Mudge 

 had thought when he finiflied this machine, that it was alto- 

 gether unneceflary to apply oil to this part, as he mentions in 

 a letter to his excellency the Count de Bruhl, upon the fub- 

 Effefl when oU je6i of its flopping; and in the fame letter he writes to the foU 

 V applied. lowing effeft, that when he had applied oil to the pallets, the 

 watch went as well as before, or, as it did when firft fet 

 a-going; that the arcs of vibration had fallen off but a few de- 

 grees, yet the watch went ten feconds a day fafter than the 

 lafl-mentioned rate, and from any thing that fuggefted itfelf to 

 him, he could not fee why it fhould not have gone rather flower 

 than fafter through length of time. I will venture to fuppofe 

 the following to have been the caufe of the machine going 

 fafter, and of the balance meafuring faialler arcs in confe- 

 quence. 

 Explanation* ^'^^ points of the teeth of his 'fcape wheel had become 



The teeth of the fliorter * by conflant wear, however fmall, and efcaped the 

 ](horter'^°efca ed P^^^^^^ ("'" rather hooks of the pallets, as they have been 

 fooner, and termed) fooner ; therefore the oppofite pallets which impelled 

 C^"0 the crank gave the impiilfe fooner to tlie balance, and in my 



mind, the watch may be fuppofed to have accelerated its rate 

 from this caufe; on the other hand, by the wearing of the teeth, 

 the wheel did not wind up the remontoire fprings quite fo 



♦ Jlefer to tjie figure, Philof. Journ. 4to feries, Vol. II. p. 49. 



