Line of position.
Comstock, George Cary, 1855- **E5118.49 The Sumner line or line of position as an aid to navigation. Ist edi- tion.
— New York. John Wiley & Sons, Inc. 1919. vi, 70 pp. Maps. Dia- grams. Tables. 15% cm,
This card was printed at the Boston Ge Public Library, January 20, tyz1.
M708 — Line of position.