Page:Report from the Select Committee on Steam Carriages.pdf/56



Mr. G. Gurney. 5 August, 1831. ; is there; riot the means of calculating pretty well the expenditure necessary to work them? The expence of fuel for working them is well ascertained.

Having ascertained that it will evaporate nine gallons of water in an hour, you come pretty nearly to the expenditure of one horse power?—It does not follow in all cases, that one horse power will be practically produced from pine gallons; and on the other hand may state, that I have seen a horse power produced from five and six gallons.

At what pressure?—It does not signify much at what pressure.

You say that the evaporation of nine gallons of water is equal to one horse power; does it not make a difference according to the pressure?—This is a point unsettled at present by Engineers; some advocate high, others low pressure.

You have stated, that if you wished to increase the power of your Engine, you would increase the weight of it, and decrease the size of the wheels?—It might be done either way; the union of the two is not necessary as far as regards the intensity of power; quantity of power must be produced by an increase of weight, or by some increased or rapid formation of steam.

What is the weight of a loaded waggon, with horses?—At this moment I am not prepared to give an accurate answer, but I should think six tons.

Does that include the weight of the horses?—No.

What should you judge to be the weight of the horse usually attached?—From 14 to 16 cwt. each horse.

Would not you, by increasing the size of the cylinder, increase your power?—Yes, in direct proportion with the increase of the area.

What objection do you see to increasing the size of your cylinder, and applying it to a large waggon, so as to use Steam Carriages for the mere carriage of goods?—I think the difficulty and objection lies in the management practically, it would be difficult in our present state of knowledge and experience to manage a large cylinder very rapidly on the road; but I