Q:

What is a sand clock?

A:

Quick Answer

A sand clock, commonly known as an hourglass, is a calibrated physical timepiece that uses sand falling from an upper container to a lower container to measure a predetermined amount of time. The archetypal hourglass is a glass vessel with an upper and lower bulb, joined by a narrow neck.

Know More
What is a sand clock?
Credit: damn_unique CC-BY-2.0

Full Answer

Factors that affect a sand clock include quality and volume of the sand, quality and size of the vessel's material and the tilt of the surface the clock is placed on. Any moisture can cause the sand to clump together, inhibiting its smooth flow and preventing accurate timing. For this reason, sand clocks are sealed after being filled.

Learn more about Time & Calendars
Sources:

Related Questions

  • Q:

    How do you operate a Kienzle grandfather clock?

    A:

    Antique grandfather clocks need to be wound up regularly. TickTockTony says to pull slowly on the chain to wind the clock. Some clocks need a key or crank turned to wind it instead. Look for the winding points, which are most commonly found on the dial. Usually, there are two different winding points. Once the clock is wound, push the pendulum to start the clock moving.

    Full Answer >
    Filed Under:
  • Q:

    Who invented the 24-hour clock?

    A:

    The 24-hour clock was developed in ancient Egypt and was based upon careful astronomical observations and shadow clocks similar to the modern garden's sundial. Originally the length of these hours varied from season to season due to differing lengths of daylight.

    Full Answer >
    Filed Under:
  • Q:

    Where can you buy a clock with a stopwatch?

    A:

    A clock with a stopwatch, such as the Wernwane Digital Timer and MeasuPro CCT300 Digital Clock, Timer and Stopwatch, is available from Amazon.com. Another highly rated clock with a stopwatch is the Polder Stopwatch Timer with Clock, which is available from Bed Bath & Beyond as well as Amazon.

    Full Answer >
    Filed Under:
  • Q:

    How do we measure the length of one second?

    A:

    The simple second has a complex origin: it is measured as "the duration of 9 192 631 770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom," according to the National Institute of Standards and Technology. This highly technical definition was introduced in 1967 at a meeting of the General Conference on Weights and Measures (CGPM), an international organization.

    Full Answer >
    Filed Under:

Explore