<a href="https://en.wikipedia.org/wiki/Balance_wheel" class="extiw" title="wikipedia:Balance wheel">Balance wheel</a> of watch with spiral <a href="https://en.wikipedia.org/wiki/balance_spring" class="extiw" title="wikipedia:balance spring">balance spring</a>
<p>PRIVAT-DESCHANEL et FOCILLON
</p>
<dl><dd>Uploaded by <a href="//commons.wikimedia.org/wiki/User:Jean-Jacques_MILAN" title="User:Jean-Jacques MILAN">Jean-Jacques MILAN</a> 15:57, 12 Dec 2004 (UTC)</dd></dl>
1883
PRIVAT-DESCHANEL et FOCILLON, <i>Dictionnaire général des sciences techniques et appliquées</i>, 1883