How much did Watt’s separate condenser effectively increase the efficiency of the steam engine, according to Professor Colin McInnes?

Answer

It tripled the efficiency of the steam engine.

Professor Colin McInnes noted that Watt’s condenser effectively tripled the efficiency, meaning mill and mine owners could achieve three times the mechanical work for every unit of coal purchased.

How much did Watt’s separate condenser effectively increase the efficiency of the steam engine, according to Professor Colin McInnes?
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