I feel it just to declare that, with Mr. Latrobe, I myself did believe, that with the ponderous and feeble steam engine, now used in boats, they could never be made useful in competition with sail boats, or to ascend the Mississippi, esteeming the current more powerful than it is. But I rejoice that, with him I have been mistaken ; for I have lived to see boats succeed well with those engines ; and I still hope to see them so completely excelled and oat-run by using my engines, as to induce the proprietors to exchange the old for the new; more cheap and more powerful principles.
When we reflect upon the obstinate opposition that has been made by a great majority to every step to wards improvement ; from bad roads to turnpikes, from turnpikes to canals, from canals to rail-ways for horse carriages, it is too much to expect the monstrous leap from had roads to rail-ways for steam carriages, at once. One step in a generation is all that we can hope for. If the present shall adopt canals, the next may try the rail-ways with horses, and the third gene ration use the steam carriages.
But why may not the present generation, who have already good turnpikes, make the experiment of using steam carriages upon them ? They will assuredly effect the movement of heavy burthens, with a slow motion, of two and a half miles an hour ;"and as their progress need not be interrupted, they may travel fifty or sixty miles in the 24 hours. This is all that I hope to see in my time, and though I never expect to be concerned in any business requiring the regular trans portation of heavy burthens (on land), because if I am connected in the affairs of a mill it shall be driven by steam, and placed on some navigable water, to save land carriage—yet I certainly intend, as soon as I can make it convenient, to build a steam carriage that will run on good turnpike roads, on my own account, if no other person will engage in it ; and I do verily believe that the time will come when carriages propelled by steam will be in general use, as well for the transport ation of passengers as goods, travelling at the rate of fifteen miles an hour, or 300 miles per day.
It appears necessary to give the reader some idea of the principles of the steam engine which is to produce such novel and strange effects ; and this I will endea vour to do in as few words as I can, by showing the extent to which the principles are applied already.
To make steam as irresistible or powerful as gun powder, we have only to confine and increase the heat by fuel to the boiler. A steam engine with a working cylinder only nine inches in diameter, and a stroke of the piston three feet, will exert a power sufficient to lift from 3,000 to 10,000 pounds perpendicularly, two and a ball miles per hour. This power applied to propel a carriage on level roads or rail-ways, would drive a very great weight with much velocity, before the friction of the axletree or resistance of the atmos phere would balance it.
This is not speculative theory. The principles are now in practice, driving a saw-mill at Manchacks on the Mississippi; two at Natchez, one of which is capa ble of sawing 5000 feet of boards in 12 hours ; a mill at Pittsburgh, able to grind bushels of grain per hour ; one at Marietta of equal powers ; one at Lex ington, Ky. of the same powers ; one, a paper mill, of the same; one of onefourth the power at Pittsburgh; one at the same place of three and a half times the power, for the forge, and for rolling and splitting sheet iron ; one of the power of 24 horses at Middletown, Conn. driving the machinery of a cloth manufactory; two at Philadelphia of the power of five or six horses; and many making for different purposes : the prin ciples applying to all purposes where power is wanted.
A, the boiler; B, the working cylinder; C, the lever beam; D, the fly-wheel; E, the condenser; F, the water-pump; G, the supply pump; II, the furnace; I, the chimney flue; K, the safety-valve, which may be loaded with 100 or 150 lbs. to the inch area; it will never need more, and it must never be fastened down.
The boiler being filled with pure water as high as the dotted line, and the fire applied, the smoke enters the centre flue, which passes through the centre of the water to ascend the flue I, and thus acts on a large surface.
When the steam lifts the safety-valve, it is then let into the cylinder by opening the throttle-valve, to drive the piston up and down, which, by rod 1, gives motion to the flywheel, and wheel 2 gives motion to a shaft, passing through the posts, to turn the spindle of the rotary-valves 3, 8, which lets the steam both off and on the cylinder at the proper time.