Measurement of the level of a liquid is needed in many hydrodynamic situations. In the present article, this has been achieved with a conductivity sensor for the specific case of water levels. The use of this system is illustrated by the automation of a gasometer in which the gas is collected in an inverted measuring cylinder resting in a water…

Describes experiments using fluidyne engines. These engines (which have liquid pistons), started by external heat sources, are used primarily for pumping water. Examples of various engines built from U-shaped tubes or from coiled tubes in fruit jars are provided. (DH)

Describes a nineteenth century paper by Reynolds on his experiments with the tension that a column of liquid could sustain, and compares Reynolds work with some of the other related work published in French journals at that time. (GA)

Examines hydraulic jumps and suggests several simple experiments which can be carried out with limited equipment. (DS)