Page:Report from the Select Committee on Steam Carriages.pdf/137



Mr. Richard Trevithick. 12 August, 1831. expanded; it was entirely cooled by itself; but when it came to touch the cold sides of the cylinder, it hung about them like a dew; the moment there was a communication to the condenser, that instant it expanded, and it threw itself into a second ; the next stroke threw that heat again into the side of the cylinder, the weight of the cylinder was about six tons; if it had taken out one degree each time, that would have taken out more than the Engine burnt. There is a clear proof how quick cold will condense.

Are there not Steam Engines in which the cylinder is within the boiler?—Yes; those are commonly used now in the high-pressure Steam Engines.

Have you ever considered what toll should be charged upon Steam Carriages, assuming that a Steam Carriage of 40 cwt, is equal to four horses, and does no more damage than four horses would do upon a road?—I should judge that there would be no need to fix them heavier than just to pay for repairing the road, whatever it may be; people are not to get their maintenance out of roads; and if the Steam Carriages do not injure the roads half as much as a common carriage, they should not pay half so much.

You do not suppose that a Steam Carriage weighing four tons would do more injury than a horse carriage?—A Steam Carriage with the same weight would do nothing like the same injury as a horse coach, for they have narrow wheels and these have not; and there are no horses' feet.

Your opinion is that there should not be a higher toll charged upon those Steam Carriages than upon a coach drawn by four horses?—If the toll is charged according to the injury done to the road, it would be not more than half.

Do you conceive there would be any difficulty in applying Steam Carriages to the present roads with the present ascents?—Under the present circumstances there is a difficulty; it is a question whether it shall go over the road, for the weight is too great; but if the weight is done away, and three to one in power added, it will be possible to do it, and I have 110 doubt it will be effected on my principle.