154 I. P. Kocu. 
veying the sights to the reticules of the respective telescopes were 
measured. 
In Fig. 11 О is the Observatory, 5 the rocky knoll on the “Skerry’ 
and I the position of the universal instrument. 
ZA owas aol 
OS was determined at 12286.0 m 
DIE er - 12282.8 т 
ES a — - 5.01 m 
O The altitude of the centre of the wooden dise 
in S over I was 0.73 m. 
The altitude of the centre of the wooden disc 
in $ over the rock was 1.51 m. 
As sighting mark to O was used the middle of 
the top of the whitewashed wall of the Observatory; 
this sighting mark lay 0.05 m lower than the reticule 
of the telescope of the Observatory, and 1.4 m nearer 
I than the reticule. 
By means of the quoted elements and the zenith 
Ay distances given below the corrections of the zenith 
distances measured were computed at: 
S from O0 5: Az — 11272) 
ie from I to O: dz, = = 0”.8. 
Results of the two observations made on July 20th 1908 by 
WEGENER (the Observatory) and Косн (the “Skerry”) in exactly the 
same manner as those between the Observatory and Cairn X: 
— = | 
Temperature | Baro- | Degree | 
| of Laer 
Date Hour —| meter |moisture | “1 ” 22 
ОО 
ml | | 
| oe 
3 | 
| | 
k 
20. July 08 | 7840 | + 6.0) + 2.1 | 753.7 | 13° |0°0144”.5 | 90°02'31”.4 90900'46”.9 198”.3 | 0.499 
— 8240 | 7.3 | + 2.3 | 753.8 | 65° 54.7 | 0302.6 01079 | 250.5 |0.368 
Mean.. | 90200’57''.4 | 
The value here determined i. e. k — 0.434, which corresponds 
to the two observations of July 20th is of course still more uncertain 
than the above-mentioned value of k between the Observatory and 
Cairn X. 
Relative determinations. 
Besides the reciprocal, simultaneous observations — and the 
levellings at the horizon, which will be mentioned later on — we 
0.434 
