PROBLEMS 75 
Case II (L. H. A. between 90° and 270°)—Problem 8.—On June 22, 1928, about 
6 p. m., the U. S. S. West Virginia in D. R. position lat. 50° 55’ N., long. 30° W.., 
observed the sun’s lower limb as follows: Watch 65 5™ 30s, C—-W. 25 1™ 20s, 
chron. fast 0™ 208. True alt. 17° 14.5’. Required line of position. 
hea 8 
Wes o 5 ee ee ) 5) ah) 
Opa ote Gu 2elen20 
Chnoshe Sn Be 8 6 50 
(Oj GS Wes SURE alae nati (—) 0 20 
GC. E:'22 June--__- 20 6. 30 
1201 een (—) 1 50.6 
(CAM TD a 20 4 39.4 
Subtract... 22252— 12 
(Cape An Se ot oe eS 8 4 39.4 W. 
Atos 33 eee 121° 9.8) Wi 
Assum. long-...(—) 30° 9.8’ W 
iets Aus es ees 91° 00’ W. (illustrates Note 13 (a).) 
180° 
Gn 8 Me ea pe eee 89° 
Emeansorlad 23° 26°77 N: 
Pea ol fo. 0! 4816. 8: A 10946 C 201 Z’— 1°3 
d+b6 22 38.1 B 41470 D 380 
lh ALS Pe A+B 52416 | C+D 581 Lieto 
he te ZN.740 W. 
a 9.7’ (away) 
MERIDIAN ALTITUDES 
A new and short method for working meridian altitudes is here developed. 
(Refer to fig. 1, p. 67.) When the heavenly body is on the meridian, ¢ equals 
zero. ‘The side a becomes zero, and point D coincides with point Z; b therefore 
equals the colatitude. Likewise, B will equal the coaltitude. Since B equals 
co (d+), itis apparent that (d+-6) will equal h (the computed altitude). Hence, 
whenever ¢=0° (when the body is on the meridian or near enough to the meridian 
such that the assumed longitude makes ¢=0°) the work of finding the resultant 
latitude at the time of the sight is exceedingly simple. Subtract the D. R. lati- 
tude from 90°. This value equals b. Apply the declination in the usual manner 
to getd+b. This value of d+ 6 equals the computed altitude (h,), except in one 
case when it exceeds 90°, in which case use the supplement as h,. Applying the 
observed altitude gives us an altitude difference. Now, the azimuth is assumed 
to be 0° or 180° according as the observer faces the elevated pole or has his back 
to the elevated pole when taking the sight. The latitude is thus quickly obtained 
without entering the tables. This method is much more simple than the usual 
methods of meridian altitudes given in Bowditch. It has the added advantage of 
disposing of the necessity of remembering confusing signs, An example follows: 
