286 1. P. Косн. 
Rough Computation. When the sun is near the meridian 
one may, in high latitudes, as the first approximation put the azi- 
muth equal to the hour angle. Seeing that an examination of the 
midnight latitude (see p. 267) as in the preceding example gives 
clock correction + equation of time equal to about — 14" we get 
Wiebe yi: een они 12h29m 
Clock correction + equation of time... — 14m 
Apparent. tun eos en. er. 128151 — МЕ 
Computation 
а ic 12h29m00$ + 1h30m — с 138.0 т observation 
Correction. 2 — 16 27 
Equation of time —(— 3 49) 
EN SEERE ERR 12h16m22s — 184°05’.5 
Read zen 765157 
Over US DER + 44 
Вос 2:17. + 456 
Ben — 15 59 
Geocenthic see 717231 260, oe el 91904 
log taney: ae 9.53190 По а 8.85452 
SEC Las Аа 0.00110, COS ыы 9.97609, 
log tan M ...... 9.53300, cosec (9 + M) .. 0.01013, 
I SEES ее 161°09'.6 log tan are 8.84074 
DM eue --77°40".3 ое 183°57'.9 
Horizontal circle .... 165 49.5 
Meridian point...... 341°52’ 
Peak NO 42. 32 ace 44 33 
Azimuth of Peak Nr. 42 $ 62°41’ W 
If one makes a comparison with the value of the azimuth of 
Peak No. 42 as determined in the course of the afternoon, one sees 
that the difference between the two values is only three minutes. 
The value of the midnight azimuth computed on the basis of 
the hour angle, а = 183°57'.9, may thus only be encumbered with 
an error of a few minutes. Knowing this, it may be of interest to 
perform the controlling computation of the midnight azimuth on the 
basis of the zenith distance, in order to form an idea of the impor- 
tance which can be ascribed to a control of this kind. 
