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. By Nevil Maskelyne, F.R.S. Astronomer Royal - Maskelyne, Nevil 1732-1811 (printed by W. Bowyer and J. Nichols, 1772)
A lecture read to the Royal Society on May 28, 1772
English Short Title Catalog, T59672
Reproduction of original from British Library