132 I. P. Косн. 
graduations'). In this manner it might just have become possible 
to compute a micrometer correction. This, however, did not take 
place; I have simply taken the mean of the 2 (4) readings. 1 divi- 
sion of the level 47.70. The barometer was read off in the “Villa”; 
the temperature given in parenthesis is that of the barometer. 
Under the column “Star; clock time” the clock time of the 
culmination has been given, in preparation of the observation, while 
the moment of observation is recorded in the course of the observa- 
tion itself. The idea was to insure against the observation falling 
too far outside the meridian, which was to be feared, as we did not 
use a meridian mark. We might possibly make a reduction to the 
meridian by means of the hour angle observed. 
The level corrections are, as will appear, not added to the 
zenith distance but to the reading of the vertical circle. 
From the observation table it will appear that stars have been 
observed, the zenith distance of which far exceeds 50°. The reason 
of this is that the aim of the measurements was a twofold one; 
partly to determine the latitude and partly to investigate the astro- 
nomical refraction. 
Measurement of zenith distances 8/IX 1907. 
Observer: Koch; Assistant: WEGENER. 
| 
57203 | b t 
21h07m 754.8 (+163) | +49 
BDOS KR 755.5 (CE 160) 5,6 
По 7537 (Г 7355) | = 62 
— — 
| ch | Microscope Level 
Star; clock time С Teese. 2 ire | rain (ER = 
| nation | | | I m) 2 Obs. Obj. 
— == = = == = 7 = = 7) = = = = = = = = = T == Tree 
n Pegasi, 3.1 | S W | 470.2 312°5208" | 51' 59" | | 
21h20m27s | | | | 50 56 | 312°51’48”.0 | 48 | 20.3 
20 14 | | 10 -| 52 00 + 0.2 | +005 
50 53 | 
| 312 52 09.0 | 51 27.0 
1) The double readings of microscope II are due to the fact that, in moist weather, 
the one of the parallel threads of the microscope was bent. In this case we 
only used the undamaged thread, making it coincide first with the one and 
then with the other side of the graduation in question. 
A careful test proved that the mean of the corresponding two readings 
had the same accuracy as the reading of an ordinary coincidence, made by 
making the graduation bisect the space between two undamaged parallel 
threads. 
