26 Mr. J. H. Poynting on a method of [Nov. 21, 



Determination of (B + X) -(A + Y). 



Weight in 

 pan. 



Extremities of 

 oscillations. 



Resting point. 



Mean of pre- 

 ceding and 

 succeeding 



resting points. 



Differences. 



A + Y 



291-7 

 275 

 289-5 



282 -80 







B + X 



261-0 



280 -3 

 263 -4 



271 -25 



282-85 



11-60 



A + Y 



285 -7 



280-4 

 285 -1 



282-90 



271-61 



11 -29 



B + X 



280-2 



265-3 

 277-5 



272 -07 



283 -90 



11-83 



A + Y 



294-9 



276-1 

 292-5 



284 -90 



273 -43 



11 -47 



B + X 



276-0 



273-9 

 275 -4 



274-8 



286 -40 



11-60 



A + Y 



267 3 



305-4 

 273 '5 



287-90 



275 -11 



12-79 



B + X 



278-5 



272 -9 

 277-4 



275 -42 



289-28 



13 86 



A + Y 



296-6 



285-5 

 295-1 



290-67 







Mean (B + X) - (A + Y) =12-06 divisions. 

 .-. (B + X)- (A + Y)=0-1500 milligramme. 

 Greatest deviation from the mean =1'8 division =0*01224 mgm. 



The previous determination of (B + X) — (A + Y) was '0718 mgm. 

 The difference is too great, "0782 mgm., to be accounted for by errors 

 of experiment. There must have been some deposit on one of the 

 weights, either of dust or moisture. I therefore took them out, 

 cleaned and adjusted them by scraping B till nearly equal to A, and 

 removing the wax from A. 



