BappickeEr—On the Changes of the Radiation of Heat from the Moon. 329 
CoLumn X.—e denotes the moon’s apparent elongation from the point opposite 
the sun (— before, + after, full moon), calculated by the formula— 
cos (r—e) =sin D sin 6’ + cos D cos 8 cos (A —a@’). 
Where A = the sun’s right ascension. 
D = the sun’s declination. 
a’ = the moon’s apparent right ascension. 
5’ = the moon’s apparent declination. 
This formula, where (7—€) represents approximately the moon’s apparent illumi- 
nated phase, is taken from the Paper of 1873, p. 593. 
Cotumn XI.—The correction for phase has been applied to &,* in Column XI., 
after 0° 12™ (or the last contact with the shadow), by means of the Phase Table, 
l.c. p. 605, assuming simple proportionality. It appears somewhat doubtful 
whether this correction should be applied immediately after the last contact with 
the shadow : its effect on the heat curve is, however, but slight, in any case up to 
0" 50", and after this time, the influence of the phase will doubtless become 
perceptible. 
Cotumns XII. ann XIII.—The values in Column XI. after the total} phase 
were now laid down as ordinates with the time as abscisse, and a curve was 
carefully drawn and read off. These final values are given in Column XIL., 
and their differences from the corresponding figures in Column XI. are to be 
found in Column XIII. 
The heat curve is reproduced on Plate IX., which also contains the necessary 
explanations. 
6. The observations of the moon’s radiant heat, made in order to obtain a 
reliable value for full moon, are given in the following Table. Their number is 
rather limited, but no more opportunities offered themselves, and I did not 
consider it advisable, after having waited for so long, to delay still further the 
publication of this Paper. The necessary explanations will be found further on. 
