Fortin type barometer

A simple Fortin type barometer can be improvised for the junior laboratory. The glass tube is held vertically with single end in the reservoir by two curtain-rod holders on wooden blocks, fixed to the back board, which is a part of 18 cm by 2.5 cm white- wood. The reservoir is a potted meat jar or small beaker, which can be enthused bodily up or down by the screw jaw of a G-clamp. This changes the level of the mercury and keeps it in contact with the bottom of the scale. The reservoir is stopped from slipping sideways by a brass collar, fitting loosely and attach to the back board.