Survey of Northeast Greenland. 151 
Ås an example of the reciprocal measurements, I shall here give 
the first mentioned of the observations quoted below. 
The Observatory, 11th August 1907 
Observer and assistant: WEGENER 
Begun 1P30; finished 1P43 
i = + 8.0; b = 757; degree of moisture 49/0; wind WNW 3m; 
cover of clouds 2°, a—cu; 1 division of the level 5”.4. 
Telescope left Telescope right 
Microscope | Level | Microscope | Level 
I fs ae О I Nr Don бы 
| | | Er | ERE 
86944'44" | 4440" 192 | 67 | 273 01190010 01580010 10.5 19.5 
48 48 15.4 6.7 | FSR =| зе 10.5 19.4 
49 ENTER: 22 el) Sah 102,102 
45 43 15.6 | 6.9 | 20 39 | 10.2 | 19.2 
2 —'86°51'28".2. 
u 
Cairn X, August 11th 1907 
Observer and assistant: KocH 
Begun at 1P25; finished at 1P50 
{— + 9.0; wind WNW 2m; cover of clouds 7°, a—str.; haze, glimmer; 
1 division of the level = 22”.5. 
Telescope left Telescope right 
Vernier | Level Vernier | Level 
A | B | Obs. | Obj. A | B | Obs. Obj. 
266°50'.6 5L.AN he ES 93°09' 3 09'.0 25 10.1 
50.6 51.100 130 53 | 09.3 09.1 2.4 10.1 
И 5.2 | 093 | 091 2.5 10.0 
506 | 51.0 128 | 52 | 09.3 OOS We 10.1 
50.5 51.0 12.9 5.3. | GE e090, <P a |< 1053 
50.6 51.2 | 128 | 5.2 | 09.3 DE По 10 
50.6 51.1. | 12s 5.2 | 09.2 | 09.0 27 | 103 
Su etd 128152 | 09.5 09.2 28 | 103 
HOG Mt DED) 11127218 РИ 09.4 09.2 2.8 10.8 
| 
50.6 51.1 12.9 5.8 | 09:3. | - 09.2 DÅ 10.0 
z = 93°09'40".2. 
The mean error of the single observation with the instrument 
of the Observatory is a couple of seconds. From the example quoted 
of the series of observations made with the small instrument one 
gets the immediate impression that the observations are particularly 
good. However, we must not overlook the fact that here, where 
