Directions for using the new improved Hadley's quadrant; with the new method of adjusting the glasses for the back observation. ... Made by P. and J. Dollond, ... in St. Paul's Church Yard, London.
P. and J. Dolland (Opticians : London, England)
[London,
1772?]
Includes: 'Directions for using the Hadley's sextant to determine the longitude at sea'.
Sig.B8 (pp.30-31) is not present.
With a half-title.
ESTC