Bamboo crafts sandglasses

*conception of environmental protection *recycable *exquisite & popular *reasonable price & high quality *lovely & harmless

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, hence the nickname eggtimer for three minute hourglasses). Today, hourglass collecting has become a niche but avid hobby for some, with elaborate or antique hourglasses commanding huge prices.

Whilst they are no longer widely use for keeping time, some institutions do maintain them, the Australian parliament uses an hourglass to time certain procedures such as divisions.

Bamboo crafts sandglasses