Show device converts auto cylinder into air pump A new device that can be screwed into the spark plug hole of one of the autos cylinders turns that cylinder into an air pump that will produce two and a halt cubic feet of free air per minute this much air Is sufficient to spray oil paint germi cide insecticide and liquids bays popular science monthly on the down stroke of the piston in the cylinder to which the device Is fitted the piston sucks in outside air through a spring operated valve on the up stroke this valve closes and another opens allowing the air to flow into a storage tank or into the pipe leading to the spray equipment it more air Is needed than can be obtained from one cylinder in this way two of the devices can be used at the same time so as to double the output it Is designed to work at an engine speed equivalent to a road speed of 20 miles an hour |