244 ON THE LIGHT OF THE MOON AND OF THE PLANET JUPITER. 
v 148,6 
154.6 
159.0 
160.7 
167.0 
167.0 
179.8 
It is plain that M, and M, alone furnish a tolerably approximate representation of 
the data. The agreement of these is good, considering the difficulties of the observa- 
tions. The largest discrepancy is for the full Moon, v = 179°.3; unfortunately, it is 
the only determination for this phase, and, the sky at the time being partially clouded, 
Log. Mi — log. Mo. Log. Ma — log. My. Log. Ma — log. Mp. 
+ 0.195 
+ 0.210 
+ 0.065 
+ 0.003 
— 0.022 
— 0.048 
— 0.200 
+ 0.129 
+ 0.167 
+ 0.036 
— 0.022 
— 0.034 
— 0.059 
— 0.200 
+ 0.062 
+ 0.179 
+ 0.112 
+ 0.062 
+ 0.001 
— 0.075 
— 0.154 
only a small weight can be given to the observation. 
To decide the question of preference between M, and M,, if we divide the results 
into groups of adjacent values of v, and take the means according to weights, we 
have 
o 
wee 1022 
121.7 
131.3 
135.7 
143.7 
158.7 
167.0 
179.3 
"E w (log. M, — log. M, y? 
Zw 
v = 102 and v = 179", 
the first is at least as good as the second. This proves that the 
brightness towards the full Moon is not necessarily due to a rel 
Il 
I tl l 
ll Il 
10 
13 
= + 0.056, 
"E 
Of the two hypotheses, then, for the quantity of moonlight between the limits 
Log. M2 — log. Mp. 
— 0.064 
-]- 0.045 
+ 0.004 
+ 0.033 
+ 0.047 
+ 0.044 
— 0.051 
— 0.200 
Log. M4 — log. My» Wt. 
+ 0.156 
-]- 0.191 
+ 0.052 
-+ 0.005 
— 0.028 
— 0.089 
— 0.200 
Log. M3 — log. Mg. 
fe eR 
2 w (log. M, — log. Mr 
Zw 
co 
— 0.023 
+ 0.028 
+ 0.051 
+ 0.040 
+ 0.063 
+ 0.108 
— 0.025 
— 0.154 
apparent increase of 
ative enfeeblement of 
= + 0.067. 
