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Model of Bennet Woodcroft's spiral propeller

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Model of Bennet Woodcroft's spiral propeller
Smithsonian Institution, Photo by Richard Strauss, Negative #: 2006-9730


This object appears in the following sections:

Marine Patent Models — Complete Catalog: before 1850

Marine Patent Models — Moving Forward

Screw propellers patented in England before 1851. Woodcroft's is left-most in the second row.
Screw propellers patented in England before 1851. Woodcroft's is left-most in the second row.

Spiral propeller model
Catalog #: 308,533, Accession #: 89,797
In collection
From the Smithsonian Collection

This model represents the "revolving spiral paddle, for propelling boats and other vessels on water," that Englishman Bennet Woodcroft patented in the United Kingdom in 1832. The model once formed part of the technology displays at the U.S. Patent Office, from which it was transferred to the Smithsonian in 1926.

Physical Description

The model is 5 3/4" W x 4 3/4" H x 2" D.

Date Made:
about 1832
Transfer from the U.S. Patent Office

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.


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.

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