Azimuth sundial, early 18th century.
© Science Museum / Science & Society Picture Library
This sundial is signed: 'Edm, Culpeper, London, fecit' (Edmund Culpeper of London made me). Culpeper (c 1670-1738) was an English instrument maker who is best known for introducing two important elements in microscope design: the sub-stage mirror and the tripod (or Culpeper-type) microscope. He also made theodolites, sectors, sundials and quadrants. Azimuth dials measure the horizontal angle or direction of a compas bearing.