File:Invariable pendulum00.jpg

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English: Drawing of a gridiron pendulum, a temperature compensated pendulum for precision clocks invented by John Harrison in 1726. The parallel rods are made of two different metals, zinc and steel, with different rates of thermal expansion. If the temperature increases, the zinc rods expand more than the iron, compensating for the expansion of the iron rods, keeping the total length of the pendulum constant, so its period of swing doesn't change with temperature.
Date circa 1725
date QS:P,+1725-00-00T00:00:00Z/9,P1480,Q5727902
Source German Wikipedia
Author John Harrison (1693-1776)
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Other versions Bild:Rostpendel2.png

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Date/TimeThumbnailDimensionsUserComment
current05:24, 15 February 2008Thumbnail for version as of 05:24, 15 February 2008155 × 472 (9 KB)Rotational~commonswiki (talk | contribs){{Information |Description=Invariable pendulum |Source=German Wikipedia |Date=ca. 1725 |Author=John Harrison |Permission=Public Domain |other_versions=Bild:Rostpendel2.png }} Category:Pendulum
05:22, 15 February 2008Thumbnail for version as of 05:22, 15 February 2008155 × 472 (9 KB)Rotational~commonswiki (talk | contribs){{Information |Description=Invariable pendulum |Source=Drawing by |Date=ca. 1725 |Author=John Harrison |Permission=Public Domain |other_versions=Bild:Rostpendel2.png }} Category:Pendulum

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