Henry Gregory (instrument maker)

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For the Australian politician, see Henry Gregory (politician).
Henry Gregory
Born 1744
Died 1782
Occupation Mathematical instrument maker

Henry Gregory (1744–1782) was a mathematical and optical instrument maker. Gregory was apprenticed to John Fowler in 1732[1] and was himself in business from c. 1750–1792 from premises in Francis Court, Clerkenwell, London and an establishment known as "The Azimuth Compass" in Leadenhall Street, London.[2] His company later became known as Gregory and Son.

Gregory manufactured navigational instruments, including quadrants of the type invented by John Hadley and compasses. One of his azimuth compasses traveled with the explorer James Cook on his second voyage to the southern Pacific Ocean in 1772–1775.[3] An azimuth compass is a compass fitted with vertical sights, used to take the magnetic azimuth of a star or planet. Surviving examples of the azimuth compass exist in the collections of the National Maritime Museum, Greenwich[4] and the Smithsonian National Museum of American History.[5]


  1. ^ "Azimuth compass". Royal Museums Greenwich. Retrieved 6 August 2013. 
  2. ^ "Henry Gregory's Bill Heading". Bodleian Library, Oxford University. Retrieved 6 August 2013. 
  3. ^ Wales, William. "Log book of HMS 'Resolution'". Cambridge Digital Library. p. 2r. Retrieved 6 August 2013. 
  4. ^ "Azimuth compass". Royal Museums Greenwich. Retrieved 6 August 2013. 
  5. ^ "Physical Sciences Collection - Navigation". Smithsonian National Museum of American History. Retrieved 6 August 2013. 
  • Clifton, Gloria (1995). Directory of British Scientific Instrument Makers 1550-1851. London: Philip Wilson. p. 119. ISBN 0-302-00634-6.