Survey of Northeast Greenland. 135 
To be used in the computation of the refraction it was necessary 
on the “read” zenith distances to place a roughly computed zenith 
correction. 
The reduction to the meridian is here, where the hour angles 
are quite small, computed from the simple formulæ 
1015760: x COSY cos Dan 
R, = ЗУ РН sims 10 oe GED (upper culmination) and 
2 2 
В, = re sin 34 Sn {? (lower culmination). 
2 sin (7. + 0) 
The hour angle is in these formulæ to be expressed in minutes. 
From the means arrived at the corrections of the zenith points 
are computed 
tor Sept. о, Yand 13: 47, = 71973 
108. Oct 2 and 132.42, — 110.0: 
If these corrections are applied, the latitude becomes: 
| Culm. N Cam. 5 
8. Sept. 7, Pegasi........ | 76946" 76°46'17".6 
В Urs. maj. ... | 1529) 
ÉACASSIOp =. | 13.9 
В. А. €. 4165... | 15-1 
e Androm..... | | 15.2 
9..Sept. 9 Urs. maj... . | 130 | 
IG Pegasie. .. rer 
ÉCASSiop. .... | 16.0 
В. А. С. 4165... | (LOT) 
1ыл5ерь 16 Рева! | | 18.6 
В Cassiop. .... | | 124 
В.А. С. 4165 ... | 133 | 
7. Oct. d Draconis.... | 16.6 
О’ Юта. | 10.7 
о Бара. 18.1 
13. Oct. 0 Draconis.... | | 17.2 
7 буша | | 15.3 
o Urs} maj: | 14.0 | 
| 910 | 178.9 
Result: 
From the seven culminations towards north ©, = 76°46'13".00 +. 0".6 
а » eleven ig a south ©, — 76°46'16".26 + 0.5 
Taking the mean of the two values a possible systematic error 
in the refraction may be supposed to be eliminated, and one gets 
ф = 76°46'14".6 + 0.4. 
The mean error of a single observation was 1”.7. 
