Hourglass

An hourglass that shows the passing of time through the steady flow of sand from one chamber to the other, available in a range of sizes and time intervals for a visual, tactile approach to measuring time. In physics and science lessons it can introduce concepts such as time, rate and uniform flow, and pupils can compare intervals or use it as a simple measuring instrument where an electronic timer is not needed. It is also handy for timing quizzes and classroom competitions.