Bennet Woodcroft (1803-79) was for many years the superintendent of specifications for the British Patent Office. The author of numerous British patents indices, he was instrumental in creating the Patent Office Library in 1855 and the Patent Office Museum in 1857. Trained as a weaver, he held a number of patents for textile machinery, but his great interest was steam navigation, for which he also held numerous patents. He long championed his screw propeller, overseeing a first test of it in a manually powered boat in July 1832 and arranging additional tests on steamships through the 1840s.
He received at least one American patent, for a variable-pitch screw propeller, in 1846.
Ref:
Bennet Woodcroft, The Pneumatics of Hero of Alexandria (London, 1971[reprint]), vii-ix.
Bennet Woodcroft, Screw Propeller, British patent no. 6,250, Mar. 22, 1832.
Bennet Woodcroft, Spiral Propeller, U.S. patent no. 4,444, Apr. 4, 1846.
Bennet Woodcroft, A Sketch of the Origin and Progress of Steam Navigation from Authentic Documents (London, 1848), 109-10.