In the autumn of 1836, a small steam vessel of 10 tons burthen and six horse-power was built, further to test the advantages of the invention.

This boat was fitted with a wooden screw of two whole turns.

On the 1st of November the vessel was exhibited to the public on the Paddington Canal, as well as on the Thames, where she continued to ply until the month of September 1837.
During the trips upon the Thames, a happy accident occurred, which first suggested the advantage of reducing the length of the screw.

The propeller having struck upon some obstacle in the water, about one-half of the length of the screw was broken off, and it was found that; the vessel immediately shot ahead and attained a much greater speed than before.

In consequence of this discovery, a new screw of a single turn was fitted to her, after which she was found to work much better.
Having satisfied himself as to the eligibility of the propeller in smooth water, Mr.Smith then resolved to take his little vessel to the open sea, and breast the winds and the waves.