An hourglass is made of two blow glass, in the shape of bulb, connected by a narrow neck. Grains are sealed inside the glass. And, the hourglass is kept inside a frame to make it stand vertically. The fine grains from one bulb falls into the other in a known space of time.
Depending upon the size of the hourglass, it can measure the time from a few sec. to hrs.
What is an hourglass?
A non-mechanical device which is used to measure the time is called hourglass.
What are the different names of hourglass?
An hourglass is also known as…
- Bulb clock
- Egg timer
- Sand clock
- Sand glass
- Sand timer
- Sand watch
How does the hourglass work?
The grains drop from the top bulb to the bottom bulb through the neck. When, the grains have drained to the bottom bulb the hourglass is turned upside down in order to start over again.
What are the factors that can alter the time of the hourglass?
The time of the hourglass can be altered by the following factors:
- The size of bulb.
- The size of neck.
- Volume of grain.
- Quality of grain.
- A level surface to place the hourglass
Why is it called hourglass?
Initially, the hourglass was designed to measure the time for an hour. Hence, it is called hourglass.
Who invented the hourglass?
When was the hourglass invented?
It’s believed to have been invented in the Medieval Age (5th to 15thcentury).
What is believed to be the inspiration for the hourglass?
Limitation of Clepsydra (water clock) is …
Hence, the limitations of Clepsydra (water clock) led to the invention of the hourglass.
What material is used to make hourglass?
It is usually made of glass.
Is sand used inside the hourglass?
No, real sand is not used. Glass beads, marble powder or silica is used inside the hourglass. Care is taken that the grains are round so as to make them flow precisely at an even rate.
What were hourglass used for?
- In church, it was used for keeping track of the sermon preached by a priest from the pulpit.
- In ships, it was used to measure the speed until it was replaced by the chronometer.
- In the workplace, it was used to give breaks to the workers.
Is hourglass still used?
It is rarely used nowadays, but it is still used for…
- Children’s board game timer
- Egg timer
- Souvenir or novelty gift!