Sundials and Hourglasses

The two exhibits I chose to show you are two unconventional and maybe even primative clocks who are no longer popoular; the Sundial and the Hourglass, more known as the Sand Clocks.


Exhibit No. 1: The Hourglass

The Hourglass is created by two glass that are placed one above the other with a very small hole between them. One of the glass is filled with sand, that flows through the other glass. In most Hourglasses, we know an hour have past when the upper glass is empty and the lower glass is full with the sand.


The Hourglass was said to be invented in the middle of the 3rd century in Alexandria. It was the first measure of time in history, and people actually carried it with them, as we carry analog or digital hand watch today. Nowdays, there are only few pratcial uses to the Hourglasss, and except board games and egg cooking, it isn't very popoular.


In the picture: The fresco "Allegory of Good Government" from the 14th cetnruy, which shows how old this device is.


Exhibit No. 2: The Sundial

The Sundial is maybe the "father" of the known analog clock. It measures time by the position of the Sun. In the middle of the sundial, there is a very thin object, mostly shaped like a triangle or a stick, and its shadow can tell more or less what's the hour, according to the position of the sun in that moment.


The Sundial is said to be invented in ancient Egypt, nearly 6000 years ago. With time, it became more specific and efficient, but even now, you can't tell what is the exact hour from the Sundial. There is no use for Sundials now for many reasons, the major of them is that it can't really tell the specific hour and it's not moveable, also.


In the picture: A horizontal sundial in Taganrog, from the 19th century.


These are the two exhibits I chose to show you. I hope you've learned a bit more about ways of measuring time.

Very good work, Omer. I really liked the way you chose to present your exhibits. Please correct your mistakes and make it perfect.
Daphna