ABSORPTION, dynamometers to measure
the useful or brake horse-power of
engines, 170-172

Account, heat, amount of heat given to
a gas engine, 226-239

Acting, single, gas engine, 3-5

twin, gas engine, 5-6
tandem, gas engine, 6
Action in Otto engine, 3-6

in Dowson gas generator, 198-201
in Mansfield oil gas plant, 202

in Mansfield sawdust gas apparatus,
205

in Thwaite gas plant, 209-214
Actual horse power, 7

Air pump, Premier gas engine, 56-59
Diagram, 59

Air valves, 117-120