SAND GLASS TIMERS lTRANSAN TIMERSI (2117) A set of three individual timers (sand glasses) to demonstrate the passage of time in three different measures. Each timer comprise of two funnel shaped vessel joined bottom to bottom to form a central constricted portion and filled with sand. The time taken by sand to drop from upper vessel to lower through the constricted portion gives the measure of timing. All the three timers have different coloured caps for easy identification of their timing. Qty :