112 I. P. Kocu. 
so that the star is made to pass fairly through the centre of the 
field, without, however, moving along a horizontal thread. 
The level may now be read off and reversed. 
About five seconds before the appearance of the star on each 
thread the observer announces “Ready” and then “Now”, when the 
star crosses the thread. The assistant notes the transit from the watch. 
The level is read off, perhaps read off, reversed and read off. 
c. The universal instrument is reversed. Second observation of 
Polaris. 
Otherwise the operations mentioned above are now repeated 
with every succeeding transit. 
4. Comparison of watches. 
5. After the conclusion of the observations of the evening, the 
instrument is greased and covered. 
Notes as regards the computation made intheobservation 
table. 
The level should indicate the elevation of the western end in 
level divisions. It appears that the inclination of the axis has been 
rather different in the case of Polaris and the equatorial star, 
which is possibly to some extent due to a slight flexure of the axis. 
When fixing the level correction it is, however, taken for granted 
that the inclination of the axis is the same in the case of Polaris 
and the equatorial star and equal to the mean of the two values. 
The reduction to middle thread might have been omitted in the 
example quoted, because here where all transits across all threads 
have been observed, it has no influence on the ultimate result. It 
should, however, always be done, because in that manner one gets 
a direct and very good idea of the accurracy with which the tran- 
sits have been observed. As regards the reduction to middle thread 
see further pp. 92 and 106—107. 
Besides the observation mentioned above there was made one more 
determination for time on the same evening. The latter was as follows: 
Determination for time 24/IX 1907. 
Observer: Косн; Assistant: WEGENER. 
| | | я 
Mag. | 57203 | = | Horizontal 
| circle 
Polaris 21 |  Oh23m Ile | BILSYN 
В Arietis | POE 0280 115652 | 
а Arietis | 22 | 0 39.5 53 .8 
E! Ceti БИ 9045) 1.16814 | 
| 0588 | 68.7 | 30925' 
& Ceti 4.3 
