
Hourglass alternatives
Hourglass, also known as sandglass, is an instrument used for measuring the passage of time. It comprises two glass bulbs connected vertically by a narrow neck that allows a regulated trickle of material (historically sand) from the upper reservoir into the lower one. Factors affecting the time interval measured include the height of the upper bulb, the ratio of the neck length to its diameter, and the precise location of the upper reservoir relative to the gravitational force.
It has been around for centuries, and through the ages, it has served many purposes. The ancient Greeks and Romans used hourglasses to tell time, with sand flowing from the upper chamber into the lower one. In medieval Europe, monks used them to remind them of when it was time to pray. They were also used to measure the length of a meeting and even to record the duration of a surgical operation. Its creation signals the importance and necessity of timing in lives.









































