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, (printed for G. Strahan, W. Meadows, and J. Clarke, C. Rivington, W. Innys and R. Manby [and 7 others in London],, 1735)