The description and use of a new astronomical instrument, for taking altitudes of the sun and stars at sea, without an horizon; together with an easy and sure method of observing the eclipses of Jupiter's satellites, or any other phoenomenon of the like kind, on ship-board; ...
Ward, William,active 1735.
Smith, Caleb,active 1740.
London : printed for G. Strahan, W. Meadows, and J. Clarke, C. Rivington, W. Innys and R. Manby [and 7 others in London],
1735.
An advertisement for Heath's stock reads "This instrument is made only by Thomas Heath, .. ".
Signed in MS. on p. 20: Willm Ward. Caleb Smith.
ESTC