Analytical beam balance. This is upper part of high precision mechanical analytical scales. To the right there are little mechanical arms that load milligram weights (circular wire loops) on the scale's beam.
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/29225114@N08">Sergei Golyshev</a>
CC BY-SA 2.0
originally posted to <b><a href="//commons.wikimedia.org/wiki/Flickr" class="mw-redirect" title="Flickr">Flickr</a></b> as <a rel="nofollow" class="external text" href="https://www.flickr.com/photos/29225114@N08/2984760850">The nature of precision</a>