An explanation of a new construction and improvement of the sea octant and sextant
Subtitle: containing a most expeditious and accurate method of adjusting and rectifying those instruments for use both at sea and land : also the best disposition of the glasses, with directions for making the fore and back observations, and the several steps in the process of finding the longitude at sea ...
By: by B. Martin
Publisher: Printed for the Author
Published: 1770
Place of publication: London
Language: eng
Number of pages: 37
Subjects: Sextant; Nautical instruments
Notes: "Advertisement": p. [38].