Images(2)

John Harrison

Engraver William Holl (1807-1871)

Publisher Charles Knight (1791 - 1873)

Publisher Society for the Diffusion of Useful Knowledge (SDUK) (British, 1829 - 1848)

Datec 1845

Object number00017861

NameEngraving

MediumInk on paper

DimensionsSight: 127 x 104 mm
Overall: 257 x 158 mm, 0.007 kg

ClassificationsArt

Credit LineANMM Collection

Terms

London

DescriptionThis mezzotint of John Harrison (1693-1776) was engraved by William Holl (1807-1871) after an engraving completed in 1768 by P L Tassaert, after an original oil portrait of Harrison by Thomas King completed in 1767 and now held in the Science Museum of London. Harrison's invention was the marine chronometer - one whose accuracy was great enough to solve one of the most pressing scientific problems of the day - how to calculate longitude at sea. Harrison's chronometers were carried by Cook on his second and third voyages.SignificanceJohn Harrison was the inventor of the first accurate marine chronometer which enabled precise fixing of longitude.