An hourglass is a device that measures time. It’s two glass bulbs joined together by a skinny neck. There’s sand inside, so when you set the hourglass with the sand-filled bulb on top, the sand trickles through the neck into the empty bulb below. The hourglass maker put in exactly an hour’s worth of sand, so when the top bulb is empty, one hour has passed. The whole contraption is contained in a frame so it can be stood on either end.
Hourglassses are sometimes called ‘sand clocks,’ but they’re timers. Remember the early Egyptian water clocks? They were timers, too, until Ctesibius figured how to make clocks out of them.
Legend says that a French monk called Liutprand (Lee-UT-prond) invented the hourglass in the 8th century ad. There doesn’t seem to be solid evidence to support or deny that. Charlemagne is supposed to have owned a 12-hour hourglass—Liutprand was French, Charlemagne was French, so maybe there’s a connection? And I guess I’d have to admit that at 12 hours, that hourglass was a clock.
Back to the beginning of The Western Civ User’s Guide to Time & Space