Remarks on the Hadley's quadrant, tending principally to remove the difficulties which have hitherto attended the use of the back-observation, ... By Nevil Maskelyne, ...
Maskelyne, Nevil,1732-1811.
London : printed by W. Bowyer and J. Nichols,
1772.
A lecture read to the Royal Society on May 28, 1772.
ESTC
Also reproduced on microfilm. Woodbridge, CT: Research Publications, Inc., 1983. The Eighteenth Century ; reel 305, no. 14.