John Harrison’s Manuscripts and Drawings
These images are available from The Bridgeman Art Library
 Diagram of timekeeper movements |
 Fig 5. Gridiron pendulum designed for the construction of precision long case clocks. Fig 6. two inter-connected bar shaped balances with balance springs, proposed for the portable longitude timekeeper or "sea clock" |
 Instructions for the assembly of JH's H3 timekeeper |
 Design for the lesser watch mentioned by JH to the Board of Longitude on 19 June 1755, taken from a set of mechanical notes and drawings compiled by JH and son William |
 A page of instructions for the assembly of H4 |
 Another page of instructions for the assembly of H4 |
 The movement of H4 |
 Drawing of the layout of the movement of H4 |
 Design for a large enamel watch dial |
 Two designs for large enamel watch dials, from mechanical notes and drawings compiled by John Harrison (1693-1776) and his son William (c.1726-72) |
These images are available from The Bridgeman Art Library