A new and accurate method of finding a ship's position at sea
Subtitle: by projection on Mercator's chart, when the latitude, longitude, and apparent time at the ship are uncertain ... The principles of the method being fully explained and illustrated by problems, examples, and plates.  With rules for practice, and examples from actual observation
By: By Capt. Thomas H. Sumner
Edition: 6th ed., rev.
Publisher: T. Groom & Co.
Published: 1866
Place of publication: Boston
Language: eng
Number of pages: 90
Subjects: Sumner's method