H1 1730 - 1735
Constructed between 1730 and 1735, H1 is essentially, a portable version of Harrison's precision wooden clocks. It is spring-driven and only runs for one day (the wooden clocks run for eight days). The moving parts are counterbalanced and controlled by springs so that, unlike a pendulum clock, H1 is independent of the direction of gravity. The linked balance mechanism also ensures that any change in motion which affects one of the balances is compensated for by the same effect on the other balance.
| |
|
Harrison's linked balance mechanism negates the effects of motion of the clock.
Animation © National Maritime Museum
|
H1 was brought to London in 1735 and displayed to the scientific community. Harrison was beseiged by requests from both scientists and socialites to see the timekeeper.
In 1736, Harrison and his timekeeper travelled to Lisbon aboard the ship Centurion, as a test of the clock, and returned on the Orford. H1 performed well in the trial, keeping time accurately enough for Harrison to correct a misreading of the Orford's longitude on the return voyage. However, Harrison did not ask for a second trial but, instead, requested financial assistance from the Board of Longitude to make a second marine timekeeper.
The Longitude Problem | John Harrison | The Chronometers | Awarding the Prize | Rupert Gould
Links & References
Table of Contents
Please send any comments, questions or suggestions to us via our feedback form, or e-mail rogweb@...
All text and pictures © National Maritime Museum, except where otherwise noted. Reproduction is strictly prohibited without the express written consent of the Museum. Permission to use images can be obtained from our Picture Library.
Send Email
