Todays wallpaper: "A look through hourglass"
Before the invention of the mechanical clocks, timepieces used the sun's motion or simple measurement devices to track time.
The hourglass first appeared in Europe in the eighth century, and may have been made by Luitprand, a monk at the cathedral in Chartes, France. By the early 14th century, the sand glass was used commonly in Italy.
The hourglass first appeared in Europe in the eighth century, and may have been made by Luitprand, a monk at the cathedral in Chartes, France. By the early 14th century, the sand glass was used commonly in Italy.
So how does it work? It's pretty simple, two globes (also called phials or ampules) of glass are connected by a narrow throat so that sand (with relatively uniform grain size) flows from the upper globe to the lower. They are made in different sizes based on pre-tested measurments of sand flow in different sizes of globes.
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