Page:Report from the Select Committee on Steam Carriages.pdf/147



Mr. Richard Trevithick. 17 August, 1831. save fuel; and give a considerable increase in the power of Engines with less space and weight. I have made an entire new Engine, both in principle and arrangements, the fire-place, boiler and condenser are formed of six wrought-iron tubes standing perpendicular on their ends, encircled the one within the other for the purpose of safety, and to occupy little room, also for keeping the boiler to one constant gauge, with fine distilled water, permanently working without loss, by condensing the steam and never suffering it to escape out of the Engine, but returning it from the condenser back again into the boiler every stroke of the Engine by a force pump, and where an Engine is perfectly tight it would work for ever without a re plenish of water; but to supply leaks a small evaporating apparatus is used for supplying the deficiency with distilled water, which effectually prevents any fluctuation in the height of water in the boiler or collecting sediment, and an impossibility of ever getting the boiler red hot, there being no space for the water to fly to out of the boiler but into the condenser; and this is so small, that if by any means the force pump did not return the water regularly from the condenser to the boiler, the space in the condenser, by taking one inch in depth of water out of the boiler, would fill-and glut the condenser so, that the Engine would stand still, and, as the water cannot diminish, it does not require a large quantity of water, or water space in the boiler, so necessary in other Engines, to guard against fluctuation in the feed, and prevent the boiler becoming red hot. The boiler being considerably less, the strength and room will be increased, and, never getting hot, the Engine might be worked with much higher steam; if so high as the gasholders are charged with, the theory gives a saving of fuel, weight and room over low-pressure Engines of sixteen to one, without a supply of water. I state this, to show the probable advantages that will arise from this new Engine. For my Engine to be one hundred horse power, to raise sufficient Steam, the fire tube must be three feet diameter, which would give the boiler a diameter of three feet eight inches, and that a half