COMPARISON OF THE LIGHT OF THE SUN AND MOON. 291 
For the Moon's distance from the Earth and Sun: — 
Moon's geocentrie semidiameter' = 902.1 
Augmentation for altitude of 24° <a DA 
908.50 log. — 2.9583 
Moon’s mean semidiameter 934.67 “ == 2.9707 
0.0124 
2 
0.0248 
Log. Earth’s radius vector, 0.0063 
2 
0.0126 i y c. < 20.0128 
Log. cor. to Moon's mean distance from Earth and Sun = 0.0374 
For the imperfect illumination of the Moon's disc: — 
Angle of elongation of Moon from Sun = 1174 
Log. corresponding correction for phase,* . ; e > 0.013 
The sums of the above logarithmic corrections are: — 
Comparison (a), Log. correction — 0.224 
T (5), (e), " — 0.198 
e (4), (e) CP) 3 = 0.179: 
The distances of the foci of the globes from each other and from the Bengola give, 
after applying the above corrections, 
Bengola 
(9) Log: Image of mean Full Moon in B, SCH 
(0, (0), a — 5.587 
(4), (e); CP» 7 T SAVS 
Mean by weights, . . d : k 5.466 
Comparing this with the result just obtained for the Gët of the Sun's image 
reflected from the same globe, we have, finally, 
ER En E B. — 5.466 — 9.798 — 5.673; 
Image of mean Full Moon in 5; 
or, 
Light of mean Sun — 470.980. 
— Light of mean Full Moon 
* Derived from the table of values of log. A, in the preceding Memoir. 
