Elaborate sandglass assemble calibrated to (right to left) 15, 30, 45 and 60 minute periods respectively. The ‘sand’ in this particular piece is believed to made up of ground eggshells. Germany, 17th century. [1280×1019]

Elaborate sandglass assemble calibrated to (right to left) 15, 30, 45 and 60 minute periods respectively. The ‘sand’ in this particular piece is believed to made up of ground eggshells. Germany, 17th century. [1280×1019]