with the inquiry, whether this combination in a carriage was known there. Learning that it was not, he deposited it in evidence of his right, and subsequently made that form of a compound carriage which is described as follows:

The wheels of common carriages operate as levers of the second class, because the wheel turns on the axle; but when the axle turns with the wheels, it operates as levers of the first class, or as a windlass.

The main travelling wheels of his carriage, are of the latter kind. The fixed axles pass through the wheels, and extend about nine inches from them, on each side; the last three inches thereof being converted into smooth gudgeons or pivots. These enter the upper parts of the rims of the secondary wheels (those of the second class of the lever), which, in this modification, are placed outside the large wheels, but do not touch the ground, and are of about half the diameter of the large wheels. They have each short axles, which work in brasses, placed underneath the side pieces of the frame of the carriage, and between which they are lodged. Their rims hanging on the gudgeons, their short axles bear up the load-frame; and when the primary wheels roll forward on the rail-road, their axles turn, and the gudgeons roll in, on, and under the smooth surfaces of the rims of these outside wheels, which, of course, revolve slowly; and turn perhaps once, while the large wheels and axles revolve ten times; the bearing or rubbing axles moving thus very slowly, perhaps no attainable speed of the carriage would cause them to heat.

This form of the carriage thus requires no fixtures; but in essential parts are combined naturally together, and work without any liability to separate. Nor is there any friction but that of the small axles, which it is the object of the leverage to overcome. The friction, nevertheless, must be still there, however slow they move. Comparative slowness described by the sur

is incident to leverage. The space

faces, may be a good index of the power employed in this

case; but the experiments of Walker and others, have shown that the ratio of resistance is as the weight, nearly; and not as the velocity. Indeed, it is evident that the motion of the one end, and of the other, of a lever, is relative. The gain of power is neither augmented nor diminished, by the quickness of the application.

Thus the compound leverage of this carriage conquers the resistance of friction, and allows the augmenting the quantity of the load. The horse draws the instrument of his power, as a part of his labour. His speed, like that of the steam engine, would accelerate, till the force and the resistance balanced each other, or steadiness was attained.

(To be continued.)

VI.-On a New and Improved Plan of Constructing Iron Rail-ways and Carriages. By the Chevalier BAADER, of Munich*.

Munich, March 19th. 1828.

It is generally acknowledged by the most eminent engineers, and by the most impartial writers on mechanical subjects, that the present construction of rail-ways, and of the carriages or waggons conveyed upon them, is still very far from being arrived at that degree of perfection of which, by their principles, they appear to be susceptible; and it cannot be denied, that, upon the whole, this most invaluable invention is yet in a state of infancy.

To this imperfect state it is undoubtedly owing that these artificial roads, though known, and partially used, for a century past, have not till now been extended over whole countries, and used for all sorts of conveyance; and that the greater part of those companies which, a few years ago, had associated themselves for the establishment of rail-ways, in different directions, all over England, have been dissolved; and almost none of those numerous and

From the "Journal of the Franklin Institute."

magnificent projects, which were announced in the English papers, have been carried into execution.

It is, therefore, my opinion, that before any important and extensive plan of this kind can be adopted with a certain prospect of success, it will be necessary to bring these roads, with their vehicles, and all their other mechanical contrivances, to a higher degree of perfection, by removing all the difficulties and inconveniences to which, in their present state, they are subject.

In the first place, on the flat rails, or tram-ways, as well as the edge rails, the continual rubbing of the wheels against the upright rims of the plates, or of the projecting flanches of the wheels against the sides of the rails, cause a considerable resistance, by which not only a great part of the moving power is wasted in an useless manner, but they also tend to loosen the rails, and to disturb their foundations. These effects are particularly visible on all those sorts of rail-ways where the carriages are drawn by horses, who, by their trampling, shake the sleepers, and the whole foundations, in such a manner, that the rails become loose in a short time, and their joints are displaced; their ends stand up, and their parallelism is destroyed; the immediate consequences of which are an increased resistance, violent jolts, frequent breaking of the wheels and rails, continued repairs and delays, and the speedy destruction of the whole.

In the second place, where horses are employed, the flat as well as the edge rails, but particularly the first kind, are continually filled and covered with sand, gravel, or mud, thrown up by the feet of the horses, so that the rails often become so obstructed as to occasion a considerable resistance to the carriages passing on them.

Thirdly, with regard to the waggons or carriages used upon either of these rail-ways, their present construction is so clumsy and defective in every respect, that they hardly deserve the name of machines. As both axletrees are immoveably fixed to the body of the waggon or tram, so these vehicles can only move forwards and backwards in a

straight line, and the least deviation from the straight line occasions a very considerable rubbing and friction of the wheels upon the bottom, and against the sides or rims of the rails; and, of course, produces a great additional resistance, together with a most destructive wear and tear of the wheels and rails.

Fourthly, on such places where a rail-way ceases, or where it must be interrupted, which is unavoidable upon long lines, passing through towns, over long and narrow bridges, &c., these waggons are incapable of leaving the rails and being brought over any common roads, paved streets, or other ground. They must, therefore, be unloaded, and their contents be carried forwards upon common carriages; a very troublesome operation, and which is always attended with expense, and great loss of time.

Fifthly, one of the greatest objections to the present system of rail-ways is, that the carriages are so confined to the tract of the rails, that they cannot, like common carriages upon a turnpike-road, turn out, to pass each other, when meeting upon the same line, or where a slow moving train is overtaken by a quicker one. The siding-places, or turnouts, employed for that purpose in England, are but very imperfect contrivances. They can only be placed at certain distances, and are of no use to the carriages meeting between those places. Their management is also extremely tedious and troublesome; and though for want of a better and more convenient method, they may answer for the slowest transports; yet they will be of no service at all for quick conveyances, on account of the great loss of time attending every such operation, and of the danger of the carriages running foul of each other; because the momentum inertia of such masses, cannot be stopped so quickly and easily upon a rail-way, as upon a common turnpike-road.

Sixthly, as the principal advantages of rail-ways, and their great superiority over canals, consist in the quickness of conveyance, and in the possibility of employing mecha

nical power, instead of horses; so the loco-motive, and stationary steam-engines, have been proposed, and partly introduced in England, for the propelling of all sorts of vehicles upon rail-ways. But of all the trials which, till lately, have been made, not one has yet succeeded to such a degree as to fully answer the sanguine expectations of their projectors. The greatest speed which, with either of these engines, could be given to a train of heavy loaded carriages, without the most imminent danger of dashing both carriages and rails to pieces, hardly exceeded six miles per hour; and as the greatest part of the power possessed by the loco-motive steam-engines is absorbed by their own weight; and that of the stationary steam-engines is lost from the weight and friction of the long ropes and chains employed in drawing the carriages, so the expense of fuel is very considerable, and even surpasses the expense of horses, wherever a ton of coals costs more than eight shillings.

Being perfectly acquainted with all the newest mechanical inventions in England, and strongly impressed with the high importance of this particular subject, so I have, for these twenty years past, applied myself with the greatest assiduity to the improvement of rail-ways and carriages; and, by a constant study, and after many expensive experiments, I have at last succeeded in contriving an entirely new plan, by which all the difficulties and inconveniences above enumerated are completely removed; and the conveyance upon rail-ways is now brought by me to a degree of perfection which was scarcely thought possible.

The principal advantages of this new plan are the following:

The rails are constructed in such a manner, that the carriages move along them with the greatest facility, and without any sensible lateral friction, though the wheels are constantly kept upon their tracks. By this means, and by a more advantageous, and yet simple, construction of the waggons, the resistance is so much reduced, that, upon

VOL. VI.

D