MATHEMATICAL SECTION. 
91 
the mass of the one whose motion is sought is negligible in compar¬ 
ison with the masses of the other two. The potential function for 
the disturbed body was put in a general form for the purpose of 
ascertaining the most advantageous variables for its development, 
and some of the particular forms were derived and discussed. Mr. 
Hill also indicated the methods which might be most advantage¬ 
ously followed in the application of his theory to Hyperion. 
This paper was discussed by Mr. A. Hall, who alluded to the 
unique character of the motion of Hyperion, and stated some of the 
more interesting facts concerning the observations of this satellite 
and the failure of the theories thus far advanced to represent its 
motion. 
Other remarks were made by the Chairman and Mr. Woodward. 
[This paper appeared in fall in the Annals of Mathematics. 4°. Char¬ 
lottesville, Va. 1887, June; vol. 8, no. 3, pp. 65-73. Also separately 
printed.] 
Mr. A. Hall presented a paper on 
THE parallax OF a TAURI. 
He gave a historical account of the early attempts at the deter¬ 
mination of stellar parallax together witli some of the results at¬ 
tained. He exhibited in tabular form the principal data on which 
his value for the parallax of a Tauri depends. In contrasting his 
result with the larger value for the same star determined by Struve 
he stated that his values for parallax are generally smaller than those 
of other observers. 
The brief discussion which followed was participated in by Messrs. 
Eastman, Paul, and others. 
29th Meeting. April 27, 1887. 
Ir 
The Chairman presided. 
Present, thirteen members. 
Mr. A. S. Flint read a paper on 
THE MOST PROBABLE VALUE OF THE LATITUDE AND ITS THEORET¬ 
ICAL WEIGHT FROM ENTANGLED OBSERVATIONS OCCURRING IN 
THE USE OF TALCOTT’s METHOD. 
In this paper Mr. Flint showed first how to express the weighted 
