Brnnert—Actinometric Observations of the Solar Helipse. 375 
Thus for any value of 0, = is found from equation (8), and the 
point O is determined on AB from equations (9). 
Also A corresponds to 2" 12°6™ mean time 
Le Pon 22 5 
B KS A 2020 53 
The Nautical Almanac also gives angle from North point of 
first contact 109° towards the West 
last contact 111° towards the East 
for direct image, that is 
ACH = MCB = 70°, 
and magnitude of eclipse (Sun’s radius = 1) 1°352, 
thus 
CM = :648 (radius). 
If then we assume that AB is described uniformly in 134, the 
ratio = determines the mean time for the value of = so found. 
Thus the following points on the = curve were found :— 
") Corresponding mean time. = 
H. M. H M. 
0° 2 12°6 4 26-6 1 
30° DOD 4 16 1-061 
45° D - 26 fl 1-222 
60° 52 3 46°5 1642 
70° 3 22 — 2°343 
This is the tall curve in fig. 4. 
