Account of a new instrument for measuring small angles, called the prismatic micrometer. By the Rev. Nevil Maskelyne, ... Read at the Royal Society, December 18, 1777.
Maskelyne, Nevil,1732-1811.
London : printed by J. Nichols (successor to Mr. Bowyer),
1778.
The plate is that from the 'Philosophical Transactions', Vol.67.
ESTC