Water-bellows
A blast-machine consisting of two cisterns partly filled with water, in which are placed the induction and education pipes, both standing a little above the water. Inverted chambers suspended on the ends of a working-beam inclose the pipes within the cisterns, and as each chamber is made to rise alternately the air is drawn up through the induction-pipe into the chamber, and expelled at the eduction-pipe by means of suitable valves; the valve being at the top for induction, at the bottom for eduction.