This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book without typos from the publisher. Not indexed. Not illustrated. 1920 Excerpt ...is the same as the latitude of the point on the line A', RJ 25 19'.4 S. B115 31.5 W. We now have two Sumner linee, A'and B', under Case I, whose common latitude is 25 19MS., and whose longitudes on the common parallel are 114 61K.7 and 115 31'.5. Hence, the difference of longitude on the common parallel is 115 31'.5 W. 114 59'.7 W. CHAPTER XVI. THE PEAOTIOE 01 NAVIGATION AT SEA. 381. Having set forth in previous chapters the methods of working dead reckoning and of solving problems to find the latitude, longitude, chronometer correction, and azimuth from astronomical observations, it will be the aim of the present chapter to describe the conditions which govern the choice and employment of the various problems, together with certain considerations by which the navigator may be guided