HISTORY OF THE INVENTION. 
5 
to the astonishment of every spectator. Three days after my arrival, by desire of Admiral 
Bickerton, I got the ship under way, and went up and down the harbour to the greatest 
satisfaction of all persons who saw the exhibition. 
I believe we shall lay here some time; therefore, I take this opportunity, by one of His 
Majesty’s cutters, which sails direct for England, and now under way, of sending you the 
opinion of Admiral Bickerton, and remain, 
Sir, your’s respectfully, 
John Shout. 
Copy of opinion of Admiral Bickerton. 
Kent-Valette, Sept. 2, 1802. 
Sib, 
Having been on board the Doncaster transport, and examined the working of 
the propeller, while the ship was under way, I have to inform you that I think the plan 
a good one, and that it may, in many instances, be found useful. 
To the Master of the Doncaster. 
I am, Sir, 
Your obedient servant, 
R. Bickerton. 
These certificates do not state what “the propeller” was, but we have been 
furnished with a description of it by Mr. Napier, who, some years after this date, 
having made some experiments with a screw which he believed to have originated 
with himself, showed it to various persons, and thereby became acquainted with 
Mr. Shorter’s previous trials; and having found that person to be living in South 
wark, he called upon him at his residence, and was shown a large collection of 
models of the screw propeller applied in the dead wood, the quarter, the bow, at 
the vessel’s sides, and, in short, in every possible position. The screws also were 
varied in their form, consisting of one continuous thread, of two, three, and four 
threads, of mere vanes like a wind-mill, and of a single arm. Indeed, Mr. Napier 
states that he appeared to have contemplated every possible arrangement, and 
that his models comprised most of the modifications now before the public. He 
showed Mr. Napier a number of experiments in a reservoir he had constructed 
for that purpose in his workshop, by which it appeared that the best performance 
arose from a single blade or arm projecting from an axis, and this seems to 
have been the form he used in its adaptation to the vessels referred to in the 
certificates. The position in which he fixed them is doubtful, but the impres 
sion is that they were placed one in each quarter, the axes passing through 
stuffing boxes. 
In a work published in 1824 by order of the French Government, from the