The description, use, and excellency of a new instrument, or sea quadrant, invented by Caleb Smith, for taking altitudes of the sun, moon, and stars, from the visible horizon (as well as any other Angular Distances at Land or Sea) without impediment or Interruption from the ship's motion; whereby the Latitude at Sea May be obtained with greater Certainty, and more frequently, than by Davis's or any other of the Common Instruments. Tried, approved, and recommended by Capt. Christopher Middleton, Capt. George Spurrel, Capt. Joseph Harrison, and several other able and experienced Navigators. To which is added, An Essay to make this Quadrant serviceable at Sea, as well as at Land, when there is no Horizon to be seen. As also The Usefulness of its Application to an Aximuth Compass of a New Contrivance for discovering the Variation of the Magnetic Needle, at Sea, without any Astronomical Calculation.
- Smith, Caleb, active 1740.
- Date:
- [1740?]
- Books
- Online
Online resources
About this work
Publication/Creation
London : to be had of the inventor, at his office for insuring ships and merchandize, in Castle-Alley, over-against the West Passage of the Royal Exchange; or at the Crown Coffee-House, in King-Street, near Guildhall, London, [1740?]
Physical description
24p.,plates : map ; 80.
Contributors
References note
ESTC T31710
Reproduction note
Electronic reproduction. Farmington Hills, Mich. : Thomson Gale, 2003. (Eighteenth century collections online). Available via the World Wide Web. Access limited by licensing agreements.