ANNALS 



OP 



PHILOSOPHY. 



MARCH, 1826. 



Article I. 



On the Going of a Clock with a Wooden Pendulum. 

 By Col. Beaufoy, FRS. 



(To the Editors of the Annals of Philosophy.) 



GENTLEMEN, Bushey Heath, Stanmore, Feb. 2, 1826. 



In the Annals of Philosophy for March, 1820, and June, 

 1822, were pubhshed the descrijDtion and going of a clock with 

 an unvarnished pendulum of deal ; the regularity of time kept 

 with this kind of wood induced me to try the effect of a rod 

 made of wood of greater density ; for this purpose a very clear, 

 dry, and straight-grained piece of teak was selected, and the 

 annexed table contains the result of eighteen months' observa- 

 tions. By comparing this table with the former, it appears 

 that a pendulum with a rod of heavy wood is, in point of accu- 

 racy, inferior to one made of light, the greatest daily variation 

 of the clock with the latter being from minus 2*74'" to plus 1*48", 

 sum 4-52" ; with the teak from minus 2-52" to plus 9'o", sum 

 12'02''; whether the exactness of the time be in proportion to 

 the lightness of the wood will be the subject of future experi- 

 ments. 



I remain, Gentlemen, yours, very truly, 



Makk Beaufoy 



N(Bj« Series, vol. xi. 



M 



