On the side of the lid is a small funnel with a cock for the introduction of the piezometric liquid. A hollow brass cylinder (height 8 cm, outside diameter 3.8 cm) is screwed to the lid at the centre. A piston (diameter 2.5 cm) sealed with a leather gasket slides inside the brass cylinder and is raised and lowered by means of a large screw on the outside to apply pressure on the liquid being studied.
The piezometer, consisting of a silver-plated metal plate (height 27.5 cm, width 3 cm) at the centre of which a cylindrical glass tank (height 8 cm, outside diameter 1.9 cm) of known volume for the liquid under examination is attached, is suspended from a hook attached to the metal head of the piston. The piezometer is surmounted by a capillary pipe (length 12.5 cm) which terminates with a small funnel for filling; to one side a mercury thermometer is attached while on the other side is a manometer consisting of a glass column (height 12 cm) with the top closed.
The tank is filled with the liquid to be examined and, to separate it from the piezometric liquid in which it is to be immersed, a drop of mercury is introduced into the capillary, also to act as the index. ...continues