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| A side-profile of a Branca engine, a sort of modified aeolipile engine design. [2] |
“Branca, in his mechanical treatise (1629), this distinguished physician describes a rotatory steam engine he used for grinding his drugs. He gives the top of the boiler the form of a man's head with a pipe in his mouth, blowing a jet of steam against the arms of a wheel (adjacent figure), to cause it to rotate on its axis, and by the pinion give motion to the drug machinery. A modification of this plan was tried at the Surrey Docks, with a wheel of 11.5 feet diameter, making 500 revolutions per minute. But the consumption of steam for an equal duty being greater with the rotatory than with a piston engine, led to its disuse. Branca also describes a hot-air rotatory engine, driven by the heat and smoke collected from a smith's forge; whereby to aid the smith in his operations; but all these engines he gives as the invention of others and not his own.”— Daniel Clark (1885), An Elementary Treatise on Steam and the Steam-Engine [2]
