SIPHON BAROMETER TORICELLI (0042) Consists of a clear glass Toricelli tube with a Ubend at the lower end leading to the mercury reservoir. Reservoir has a screw cap at the top, the thread's gap being sufficient to balance the atmospheric pressure by confining the mercury vapours. A mobile indicator allows the barometer to be regulated for altitude of the place of use. Also included is a red alcohol thermometer mounted alongside the barometer tube. Supplied without mercury Qty :