Parsons turbines and compact power

The aeolipile discussed in part one and James Watt's 1775 reaction-turbine work show that the principle long predated Charles Parsons. Parsons made a turbine that contemporary industry could reproduce consistently and operate reliably. His first machine produced seven and a half kilowatts, while turbines reached 50,000 kilowatts and higher within his lifetime. Direct drive and, later, geared turbine sets converted that power into rotation of a screw shaft. For warship design, the payoff was great power from a smaller machinery volume, which reduced the amount of armor needed for protection.