Ki 
274 ON THE LIGHT. OF. THE MOON. AND OF: THE: PLANET JUPITER. 
Brightness of central element of Jupiter ` __ 
Average brightness of Jupiter . 
( Diameter of aperture = 32",47 ) 
Diameter of Jupiter ^ :/; 
dou E 
from which we shall find ` 
>| = 
„= >. Brightest parts of the Moon, ` 
> ae 
and similarly, 
9 bus d ‘Mare: Crisium, - 
fe ROE ae 
Bo lo Mave Tranquilitadis. 
BOOT Pekka i: 
April 2d. The comparisons with lamp W, diaphragm M, give, 
Log..——— =. 8.751, SC 
Log. = : 9,819, 
for the brightest. part of the Moon ; 
Brightness of, central element. of Jupiter S . 
Average brightness of Jupiter 143, E 
( Diameter of aperture = 32.47 Xs 1 
_ Diameter of Jupiter ` DT 
Correction for relative extinction = - 1.04, 
RR? 
EC 
k | 
v= 141? log. 2 = 9.871 ; 
S i : » A : Lo e . é e y ji 
and thence, 
E Y. EEN s E 
E- = Ti -Brightest part of ‘Moons 
The other comparisons give 
