OBSERVATIONS BOR LATITUDE. 
139 
The usual method of picking up the image of the star in the artificial 
horizon, is to place the eye close to the artificial horizon, thus getting a 
large field of view, and as soon as the star is identified to draw back 
(keeping the eye on the star in the artificial horizon) into a comfortable 
position for observing; then bring the star down with the sextant, and 
make a contact with its reflection in the artificial horizon. In countries 
where there is a heavy fall of dew, it is always well to keep the artificial 
horizon covered with a light cloth during the intervals between taking sets 
of observations. 
Observations for Latitude. 
The simplest observation is that for finding the latitude by meridian 
altitude of the sun , star , or planet. Some twenty minutes before apparent 
noon, when the sun is observed, or before the time of meridian passage 
of a star or planet, the observer should begin to take careful obser¬ 
vations, reading the angles from time to time until the body has reached 
its greatest altitude; this will be the meridian altitude, and the time 
when it was taken will be apparent noon, if the sun has been observed. 
Latitude by Meridian Altitude of Sun. 
July 17th, 1899.—At a place in Longitude by account 0° 48' W., the 
meridian altitude of the 0 was observed in quicksilver to find the 
Latitude. Ther. 82°. Bar. 29 6 inches. Index error -1' 20". Observer 
north of the 0. 
II. Ms S. 
Time of App. Noon, July 17th .. 000 
W. Long, in Time.+0 3 12 
G. App. Time, July 17 th .. o ] 12 
© / // 
Declination (P. I.<NA.) .. 2£ 12 20*9 N. 
(Decreasing) 
Correction .... — 1*27 
Reduced Declination 21 12 19* 6.1 N. 
n 
Variation in 1 hour (NA.) .. .. .. 25*47 
•05 
Correction.. = 1*2735 
0 
1 
// 
Alt. 0 in quicksilver.. 
•• 119 
47 
10 
Index error . 
1 
20 
2)119 
45 
50 
Refraction— ) 
59 
52 
55 
Ther. 82° Bar. 29 • 6 in j 
0 
52*4 
59 
52 
22*6 
Semidiameter ,. .. .. 
15 
45*8 
60 
8 
8*4 
Parallax. .. 
0 
4*2 
True Altitude.. .. .. 
.. 60 
8 
12*6 
90 
00 
00 
Zenith Distance .. .. 
5 i 
47*4 
Reduced Declination .. 
.. 21 
12 
19*6 
Latitude 
51 4 7 N- 
