64 D. P. Todd—Solar Parallax from the Velocity of Light. 
tion of Fidentity necessary. 
(a.) Combining the maximum velocity of light with the 
maximum coefficient in the light-equation, and the minimum 
velocity with the minimum coefficient, the following relations 
exist :— 
Limiting Limiting Distance of Sun Solar 
k Vv In kilometers In miles. Parallax. 
499°3 299990 149,785,000 93,074,000 8-782 
497°°3 299850 149,115,000 92,658,000 8822 
(6.) Combining the maximum velocity of light with the 
maximum value of the constant of aberration, and the mini- 
mum velocity with the minimum constant, the following 
relations exist :— 
Limiting Limiting Distance of Sun Solar 
6 Vv In kilometers. In miles. Parallax. 
20'°4'7 299990 149,510,000 92,903,000 8"°798 
20°42 299850 149,076,000 92 "633 000 8'"-824 
It will be remarked that all these combinations are made in 
the most unfavorable manner, so as to give the limiting values 
of the solar parallax with the variations of the elements pre- 
viously adduced. The probable errors of the ine 
values of the parallax are about one-third these variation 
In conclusion, then, all the experimental dekernitnetinae of 
the velocity of light hitherto made give, when combined with 
peevaomice constants, ie mean peal horizontal parallax 
o 8084-07006. 
The pe ae radius of the terrestrial orbit is 
149,345,000 kilometers = 92,800,000 miles. 
Nautical Almanac Office, Washington, Nov. 10, 1879. 
