Remarks on the Hadley's Quadrant, tending principally to remove the difficulties which have hitherto attended the use of the back-observation, and to obviate the errors that might arise from a want of parallelism in the two surfaces of the index-glass.
Maskelyne, Nevil,1732-1811.
London, printed by W. Bowyer and J. Nichols
1772
The first leaf is blank
Hadley, John.
Quadrant.