Page:Report from the Select Committee on Steam Carriages.pdf/39



Mr. G. Garney. 3 August, 1831. weight to be drawn and the velocity required, what diameter of propelling wheel do you think will be generally used?—Five feet; the piston of the engine should not travel more than two miles and a half per hour; therefore we may multiply from this rate to any speed we please.

What is the breadth of the tire of your present wheel?—None less than two inches; but in late experiments we found a wide tire more desirable than a narrow one, and we have increased it to about three inches and a half in width; we found that there is no increase of power necessary with a wide wheel, but I think on the contrary rather less, we have not been able to decide positively the true variation in power, but the difference is so slight, that it is not perceptible.

What is the ordinary width of the tire of wheels of coaches?—I think about two inches; in a private carriage rather under two, and in stage coaches over two inches.

Of how many horse power is your ordinary travelling Engine?—Twelve nominal Steam-engine horse power; to work eight hours it takes the common stage coach 32 horses; an Engine propelling the same weight for eight hours should be considered a 32 horse-power, according to the rule laid down by Engineers, but this is not true as to locomotive Engines.

Taking your latest improvement, to what number of draught horses would it be equivalent?—I think about 10 cwt, will do the work of a horse on the road; 35 cwt, will be about 3½ horses' work always.

You mean that it will displace about three horses and a half at a time on the road?—Yes, in each stage it will displace 3½ or 4 horses, and about 30 horses in the eight hours.

Is that in practice, or in idea?—Practice.

Is the chief weight supported on springs?—The whole is on springs.

What is the weight of an ordinary stage coach?—About 24 cwt; I think from 18 to 24.