I have your two letters of the 31st and 1st inst. before me. Since writing you the 27th, I made an experiment in order to ascertain as nearly as I could the power of the engine, and put on your wheels. This was done by laying the vessel on shore stern foremost so as to leave the wheels entirely out of the water. The Engine was then put to work at the rate of from 40 to 45 strokes and wheels turned from 160 to 180 revolutions per minute. When the water first entered them it was thrown out with great violence; but before it got any considerable depth in them the motion of the engine was impeded and in a short time entirely stopped. By this experiment I was fully convinced that the wheels would require a power far greater than this engine possesses and that any attempts to proceed with the power we have and the present wheels would be fruitless. I was also farther convinced (by getting men whose strength was ascertained to turn the wheels by hand before the operation of the engine) tho’ she has her full power and indeed considerably more than as first mentioned, I expected we would have. Now, Sir, to proceed with the experiment you recommended of closing the openings with doors will be doing nothing more than what we have already done by the last trial. I would therefore recommend that we throw two wheels of wood over the sides fastened to the axes of the flys with 8 arms or paddles, that part which enters the water of sheet iron to shift according to the power they require either deeper in the water or otherwise and that we navigate the vessel with those until we can procure an Engine of proper size which I think ought not to be less than 24 inches cylinder. The Barometer to ascertain the exact power of the engine has not as you observe been left to depend entirely on Mr. Van Ness, although I looked upon him as your Representative according to the tenor of your own letter; but Mr. Mark and Mr. Speyer have both been on the search for one and have not yet succeeded. The copper pipe for it is made and we will I believe be obliged to wait for the glass until we can get it from the glass house above Albany. I have requested Mr. Speyer, who has gone up to the Oneida country, to call on Mr. Dezang for that purpose. If you know of any to be had in New York please to inform me and I will immediately get it.