The Hourglass

When we trace back the origins of the hourglass, we can’t find conclusive evidence of its existence before the 14th century. Now 700 years later, we’re familiar with seeing sand inside hourglasses, but over the centuries, they’ve also been filled with powdered marble and crushed eggshells.

They first found importance aboard ships as aids in measuring distances traveled—an improvement over millennia-old clepsydras, or water clocks. The water clocks could be compromised more easily, even by the condensation produced on humid days. On land, however, use of the hourglass was often more symbolic than functional. While the mechanical clock (invented around the same time) and its intricate inner mechanisms prompted comparison to the movements of the heavenly spheres, the hourglass measured a set period.