126 Mr, Herschel's account of a series of observations , &c. 

 T X V z t 



W = 



T + I ^ jr + 1 ^y + 1 



^ Z+ 1 ^^ + I * 



It would be needless refinement to enquire minutely how 

 far this agrees with a strict calculation of probabilities. 



The result of the whole operation may then be briefly 

 stated as follows : 





9 2» '535 

 9 2 1 '64 



9 21 70 



Most probable mean of the whole, so obtained - - - = g^2i*'^6S 



Mean, similarly taken, but rejecting the results of the 18th and 21st 



as liable to suspicion ------- 



Arithmetical mean of all the four results - - . 



Arithmetical mean of the results of the four nights, obtained by the 



2d combination, or from Capt. Sabine's and Mr. Herschel' 



observations alone ------- 



Arithmetical mean of the 3d combination, or Col. Bonne's and "I „ ,1 '60 



M. Largeteau's observations taken separately - - . J 



On the whole then, 9*" 21 "'6 may be assumed as a result 



not very likely to be altered a whole tenth of a second, and 



very unlikely to be altered to twice that extent, by future 



determinations. 



J. F. W. HERSCHEL, 



Xx>ndon, November 2, 1825, 



