<p>Photo of instrument in Teyler's Oval Room, Teylers Museum, Spaarne, Haarlem
</p>
Siberian magnatite stone with acts as a natural magnet and can carry 200 pounds; gift of Professor G.F. Parrot of Dorpat  (today Tartu, Estonia) to Martin van Marum, 1810
<a href="//commons.wikimedia.org/wiki/User:Jane023" title="User:Jane023">Jane023</a> (<a href="//commons.wikimedia.org/wiki/User_talk:Jane023" title="User talk:Jane023"><span class="signature-talk">talk</span></a>) 23:49, 27 January 2012 (UTC)
CC BY 3.0 nl
<span class="int-own-work" lang="en">Own work</span>