opulsion of canal boats], or are you for two
wheels?" Watt added a pen-and-ink drawing of his spiral oar, greatly
resembling the form of screw afterwards patented. Nothing, however,
was actually done, and the idea slept.

It was revived again in 1785, by Joseph Bramah, a wonderful projector
and inventor.[5] He took out a patent, which included a rotatory
steam-engine, and a mode of propelling vessels by means either of a
paddle-wheel or a "screw propeller." This propeller was "similar to
the fly of a smoke-jack"; but there is no account of Bramah having
practically tried this method of propulsion.

Austria, also, claims the honour of the invention of the screw steamer.
At Trieste and Vienna are statues erected to Joseph Ressel, on whose
behalf his countrymen lay claim to the invention; and patents for some
sort of a screw date back as far as 1794.

Patents were also taken out in England and America--by W. Lyttleton in
1794; by E. Shorter in 1799; by J. C. Stevens, of New Jersey, in 1804;
by Henry James in 1811--but nothing practical was accomplished.
Richard Trevethick, the anticipator of many things, also took out a
patent in 1815, and in it he describes the screw propeller with
considerable minuteness. Millington, Whytock, Perkins, Marestier, and
Brown followed, with no better results.

The late Dr. Birkbeck, in a letter addressed to the 'Mechanics'
Register,' in the year 1824, claimed that John Swan, of 82, Mansfield
Street, Kingsland Road, London, was the practical inventor of the screw
propeller. John Swan was a native of Coldingham, Berwickshire. He had
removed to London, and entered the employment of Messrs. Gordon, of
Deptford. Swan fitted up a boat with his propeller, and tried it on a
sheet of water in the grounds of Charles Gordon, Esq., of Dulwich Hill.
"The velocity and steadiness of the motion," said Dr. Birkbeck in his
letter, "so far exceeded that of the same model when impelled by
paddle-wheels driven by the same spring, that I could not doubt its
superiority; and the stillness of the water was such as to give the
vessel the appearance of being moved by some magical power."

Then comes another claimant--Mr. Robert Wilson, then of Dunbar (not far
from Coldingham), but afterwards of the Bridgewater Foundry,
Patricroft. In his pamphlet, published a few years ago, he states that
he had long considered the subject, and in 1827 he made a small model,
fitted with "revolving skulls," which he tried