ON THE LIGHT OF THE MOON AND OF THE PLANET JUPITER. 983 
somewhat precarious nature of the theory which has been adopted for expressing the 
distribution, in various directions, of the light reflected from the planet. 
One such may be derived from Seidel’s investigations upon the light of Jupiter com- 
pared with the fixed stars.* e 
He has obtained, for the proportion between the light of the Sun and that of 
a Lyre, using Lambert's formula, 
Sun 
Log. 
i a Lyre 
= 10.4499 — log. albedo Jupiter. 
If we employ the values, 
lup ee treme tu ULM, 
a Lyre. 
Jupiter at mean opposition = 6.1918, 
Mean Full Moon 
Log. 
the first as deduced by Seidel, and the second taken from (33), we have 
= 4.7240 ; 
L Mean Full Moon. 
og a Lyre 
hence, 
Sun 
S = 5.7259 — log. u”. 
v Mean Full Moon EP 
This gives for the albedo of Jupiter 
: ich. i ubstitute 
in which, if we s S — 550000, 
the mean between the values determined by Bouguer and Wollaston, we obtain 
pr = 0.967. 
Although not much dependence can be placed in the value of St on which this 
determination rests, it deserves attention that the result is of the same character with 
Lichtstärke der Planeten Venus, Mars, Jupiter, und Saturn, München, 1859. 
* Untersuchungen über die 
jl! zzz 1.18. 
f The new determination of S, referred to in the note on p. 266, gives 
