Marine timekeeper, H3. Started in 1740, this third timekeeper took Harrison nearly 19 years to build and adjust, although it was not to win him the great longitude prize: he found that he just could not persuade the two large, heavy, circular balances to keep time well enough. Nevertheless, H3 incorporates two extremely important inventions, both relevant today: the bimetallic strip (still in use worldwide in thermostats of all kinds) and the caged roller bearing, a device found in nearly all modern mechanical engineering. See also; ZAA0034 (H1), ZAA0035 (H2) and ZAA0037 (H4).
|Display location:||Display - ROG|
|Exhibition:||Time and Longitude; Ships, Clocks & Stars: The Quest for Longitude|
|People:||Royal Greenwich Observatory|
|Credit:||National Maritime Museum, Greenwich, London|
|Measurements:||Overall display height: 622 mm|
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