140 
HtN4S TO TRAVELLERS. 
To Find Time of Meridian Passage of Star , 
When a star is observed for latitude, it is necessary to find the time of 
its meridian passage, either by tables (which give an approximate result), 
or, where accuracy is required, by the following method. 
At a place in Longitude 30° E. required the mean time of the meridian 
passage of a Tauri ( Aldeburan ) on November 27th, 1899. 
(Case i.) 
h. 
H. 
M. 
s 
R. A. of Aldebaron 4* 24* = 
28 
30 
IT 
'OJ 
Sidereal Time at Mean Noon = 
16 
24 
4 T 
■98 
Approx. M. T. — 
12 
5 
29- 
05 
M. S. 
12b. Retardation 1 57*951 
5*5m. „ 0 0-9 J 
- 
1 
58- 
•85 
12 
3 
jo- 
•20 
f jo° E. Long, (or 2h.) Acceleration 
+ 
19 ' 
Mean Time of Meridian Passage = 
12 
3 
49 ' 
' 9 i 
* When the star’s It. A. is less than the Sidereal Time at Mean Noon, increase it by 24 hours. 
At a place in Longitude 60° W. required the mean time of the meridian 
passage of a Scorpii ( Antares ) on July 30th, 1899. 
(Case 2.) R. A. of Anta\ 
51 *5m. 
8 * 44 / 
f 6o° W. Long, (or 4b.) Acceleration — 
Mean Time of Meridian Passage =s 7 
H. 
M. 
s 
16 
2 J 
16 
'97 
8 
31 
3 T 
■48 
7 
51 
39 ' 
49 
- 
I 
27' 
25 
1 
50 
12 
■24 
“ 
39' 
‘43 
7 
49 
32- 
•81 
f When the Longitude is West subtract the acceleration, when East add It. 
Latitude by Meridian Altitude of a Star . 
July 10th, 1899.-—At a place in Longitude by account 70° 00' W., the 
meridian altitude of a Aguarii was observed in quicksilver to find the 
