Waterthief

Weston—300 feet 1½ inch hose; 50 feet 2½ inch hose; one flasher; one siamese waterthief; one foam extinguisher.

Source: wiktionary

An example is the waterthief (klepsydra). This is a tube, of which one (bottom) end is held under water, and which becomes full of water by sucking the air out of it at the other (top) end.

Source: wiktionary

The APC Tank was capable of delivering three mediums of extinguishing agents via a valved “Waterthief” three-way appliance that was connected to the P-250 pump.

Source: wiktionary

The most common control loop is called the feedback control loop. Feedback control is as old as civilization, or at least 1000 years old. Figure 17.8 shows a klepshydra, which is ancient Greek for "waterthief"!

Source: wiktionary