Drawing of a recoil or <a href="https://en.wikipedia.org/wiki/anchor_escapement" class="extiw" title="wikipedia:anchor escapement">anchor escapement</a> for a pendulum clock, from an 1896 clockmaking manual. The top piece is called the <i>anchor</i>, and the <i>escape wheel</i> is under it.  The escape wheel has 30 teeth, so when used with a pendulum beating seconds, the escape wheel rotates once per minute, allowing it to be used to turn the clock's second hand.   Alterations to image: removed figure number and dotted construction lines, changed from JPEG to 4 greyscale PNG.
George Henry Abbott Hazlitt
1898
Downloaded from <a rel="nofollow" class="external text" href="https://books.google.com/books?id=q_Q3AAAAMAAJ&amp;pg=PA19">George Henry Abbott Hazlitt (1898) <i>Abbott's American Watchmaker and Jeweller</i>, George Hazlitt &amp; Co., Chicago, fig.5, p.19</a> on Google Books