426 Intelligence and Miscellaneous Articles. 



Elliptic Motion Direct, 



whence, if a=3*53 in., the apsidal motion due to ^=0^467 in. will 

 be 2°-47 per hour, or 0°*53 per hour for y\jth inch, h. 



The 2nd and 5th groups compared give (when a is reduced 

 = 3-6 in.) 0°^50 per hour for ^^th inch, h. 



The 1st and 4th groups give {a being=3*6 in.) 0°'56 per hour for 

 jJjyth inch, b. 



The mean result of all is, that a being=3'6 inches, the .ipsidal 

 motion per hour for every tenth of an inch of ellipticity (b) will be 

 0°-52 nearly. Messrs. Galbraith and Haughton's formula gives 0°-445. 



By applying the empirical correction 0"^52 per hour for -j^jth of an 

 inch,^, so as to ehrainate the effects of ellipticity, the mean motion per 

 hour for each of the six groups of experiments is as follows, viz.- 



1st group 



2nd 



3rd 



4th 



5th 



6th 



Mean of all 



o 



11*60 per hour. 



11-73 .. 



11-54 



11-65 



11-67 



11-63 



11-637 



The experiments of longer duratioo, 

 are the following :— 



and unobserved ellipticity. 



