box 353mm x 30mm 10mm]]> box 360mm x 32mm x 17mm]]> diameter of compass itself 110 mm]]> base diameter: smaller 75 mm; larger 82 mm; height (each) 90 mm]]> internal diameter 80 mm; external diameter 105 mm; overall length 305 mm]]> Visitors' Centre caption "Late eighteenth-century mechanical demonstration from Professor Copland's cabinet, showing a cube with handles balancing beyond its edge with support under the centre of gravity of the whole shape".]]> cube side 60 mm; stand height 185 mm; handle length 170 mm; width 35 mm]]>
Tipping up the pot while holding a thumb over the air-hole above the handle, it could be filled through the spout. With the spout then firmly bunged, water would not flow out of the perforated base even when the pot was held upright because it was sealed below by the large surface tension of the water and sealed above by the thumb. Moving the thumb would cause water to be released. ]]> diameter including handle and spout 210 mm, height 125 mm]]> This is a minor gaming piece in which the 'player' moves the metals into the slots in any chose way and then closes the lid. The operator runs the compass over the lid and knowing in which direction a magnet hidden within each heart is oriented can tell which heart is in which position. Illustrating the ability of a magnetic field to penetrate a non magentic material, namely the wooden box and the metals used.]]> box 158mm x 158mm x 10mm]]>