Hourglass

An hourglass, also known as a sandglass or sand timer, is a device for the measurement of time. It consists of two glass bulbs placed one above the other which are connected by a narrow tube. One of the bulbs is usually filled with fine sand which flows through the narrow tube into the bottom bulb at a given rate. Once all the sand has run to the bottom bulb, the device is inverted in order to measure another time period.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Factors affecting the amount of time that the hourglass measures include: the volume of sand, the size and angle of the bulbs, the width of the neck, and the type and quality of the sand. Alternatives to sand that have been used are powdered eggshell and powdered marble. It is still in use, but typically only ornamentally or when a relatively approximate measurement of time is needed (for example in cooking or board games). For cooking and games the time period will be only a few minutes (for cooking eggs, a three minute timer is typical).

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Time: :For alternate uses of "time", see Time (disambiguation) or see TIME (magazine)....

Glass: :For eyeglasses, see glasses. For the drinking vessel, see glass (drinkware)....

Volume: Volume, also called capacity, is a quantification of how much space an object occupies. The SI unit for volume is the cubic metre. American spelling is cubic meter....

Hourglass related Images and Photos (experimental)

Entourage Hourglass Limousine Men's Logo T-Shirt	Vanitas Still Life with a Tulip Skull and Hour-Glass	Wizard of Oz Wicked Witch & Hourglass Salt & Pepper Shakers	Men with Puppy Overlook Hourglass-Shaped Lakes in Volcanic Crater
Wizard of Oz Wicked Witch Hourglass Statue	Face of Clock in Hourglass