John Harrison's famous chronometer
<a href="https://en.wikipedia.org/wiki/User:Racklever" class="extiw" title="wikipedia:User:Racklever">Racklever</a> at <a href="https://en.wikipedia.org/wiki/" class="extiw" title="wikipedia:">English Wikipedia</a>
CC BY 2.5
Originally from <a class="external text" href="https://en.wikipedia.org">en.wikipedia</a>; description page is/was <a href="https://en.wikipedia.org/wiki/en:Image:H5.JPG" class="extiw" title="w:en:Image:H5.JPG">here</a>. Original uploader was <a href="https://en.wikipedia.org/wiki/User:Racklever" class="extiw" title="en:User:Racklever">Racklever</a> at <a class="external text" href="https://en.wikipedia.org">en.wikipedia</a>