502 BoEDDiCKER — Oil Lunar Radiant Heat. 



Columns VI. and VII. — The factors log. p^ and log. R''^ reduce the values G to 

 the same distance of the Moon from the Earth and Sun, to those, namely, which 

 correspond to 7"" 18 '5™ or the middle of the eclipse. 



Column VIII. — e denotes the Moon's apparent elongation from the point 

 opposite the Sun (— before, + after full Moon) calculated by the formula 



cos (tt — e) = sin D sin 8' + 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, 

 8' = the Moon's apparent declination. 



This formula, where (tt — e) represents approximately the Moon's apparent 

 illuminated phase, is given by Dr. Copeland in the Paper referred to above, 

 p. 593. 



Column IX — Gives the sidereal times counted from the middle of the eclipse 

 (— before, + after). 



Column X. — The values G,* were obtained by multiplying those given in 

 Column V. with the factors in Columns VI. and VII., and fm-ther with factors 

 obtained from Dr. Copeland's phase-table (I. c. p. 605), by assuming simple 

 proportionality. This correction for phase — the effect of which is but slight — 

 was applied up to the first and after the last contact with the shadow (up to 

 5'' 28-6°' and after 9" S-i") as was done in 1884. 



Columns XI. and XII. — The G* were now plotted down as ordinates with the 

 times as abscisses, and a curve was carefully drawn and read off. These final 

 most probable quantities are given in Column XI,, and their differences from the 

 observations in Column XII. As mentioned before {supra, p. 486), the first value 

 (observed at ^^ 22-7") and those obtained from 6" 48"2"» to 8'' 30-2™ were excluded 

 in drawing this final curve. 



The two branches of the heat-curve are reproduced on Plates LIII. and LIV. 



