On May 31st, 1919, in D.R. Lat. 50° N, Lo. 45° W, G.M.T. 31d 14h 33m 30s. What was Star's H.A. at ship?
| G.M.T. | 14h 33m 30s |
| .R.A. | 4 31 44.2 |
| .C.P. | 2 23 |
| —————————— | |
| G.S.T. | 19h 07m 37.2s |
| W Lo. - | 3 00 00 |
| —————————— | |
| L.S.T. | 16h 07m 37.2s |
| Star's R.A.(Spica) | 13 20 59 |
| —————————— | |
| Star's H.A. (t) | 2h 46m 38.2s |
Now let us work out some examples by this method:
1. Nov. 29th, 1919. CT 30d 2h 14m 39s A.M. CC 3m 14s fast. D.R. position Lat. 41° 14' N, Lo. 68° 46' W. Observed altitude Star Aldebaran East of meridian 50° 29' 40". HE 29 ft. Required Line of Position by Marc St. Hilaire Method and most probable position of ship.
2. Jan. 23rd, 1919. P.M. at ship. CT 3h 45m 40s. Lat. by D.R. 38° 44' 19" N. Lo. 121° 16' 14" E. Observed altitude Star Rigel 28° 59' 20" West of meridian. IE + 4' 30". HE 42 ft. Required Line of Position by Marc St. Hilaire Method and most probable position of ship.
Assign for Night Work one or two examples similar to the above.
FRIDAY LECTURE
Examples: Latitude by Meridian Altitude of a Star, Latitude by Polaris, Marc St. Hilaire Method by a Star Sight
1. At sea, Dec. 5th, 1919. Observed meridian altitude Star Aldebaran 69° 28' 40" S. No IE. HE 26 ft. Required latitude in.