ON THE LIGHT OF THE MOON AND OF THE PLANET JUPITER. 265 
value of f H,de, extending the integration so as to include the whole surface of the 
circumscribed sphere of which de is an element; we then have, 
: fr. =f Ze äi H sin.odv = 0.463 Ze a, 
so that from (40) 
(41) e = 0,232 de: 
from which it appears that the whole amount of light reflected from the Moon is 
about one fourth as much as if it shone in all directions with the full phase. 
The quantity of sunlight incident on the Moon is, by (10), 
I6 
4 Pf’ 
and from (41), 
n D 
d i 
(42) ze Dä ed o. 
If the light of the full Moon, incident perpendicularly at the Earth, upon an element 
of surface de at the distance 4 from it, is to the light of the Sun upon the same ele- 
ment at the distance r, as 1 : S, we shall have, 
E Ll ox 
bor Dow" 
and by substitution in (42), > 
a 4 1 
— = 0.928 — —, 
ed : t a Ss 
in which we may make 
A ie 1 ) € ESO ADAM = 48700; 
p sin. Moon's semidiameter. sin.? 934".67 
and (44) becomes, 
Amount of light reflected from the Moon _ ï __ 45193 
Amount of light incident upon the Moon t S 
(45) 
Hence, by (4), the albedo of the Moon will be 
45193 
(46) prop 
It is a matter of much difficulty to ascertain S from observation, on account of the 
strong contrast between the intensity of sunlight and moonlight, and the want of a 
reliable constant light of the proper color, to which both may be referred. The obser- 
vations of Bouguer and Wollaston are notably inconsistent; the mean between them 
