The reasons which induced the intelligent citizens of Baltimore not to rest contented with the Potomac and Ohio canal, but to undertake a rail-road of unexampled extent and boldness of design, in order that merchandise from that city might reach the Ohio seasonably, are obvious; and if general considerations were sufficient to justify that resolution before the new carriage was known, how much more confidence may now be entertained, since, by this invention, the Alleghany mountains will be traversed with as much useful effect as the plains of England have hitherto been; and steam power add unexampled expedition to unprecedented economy.

While, therefore, the products of Virginia and Maryland from along the tributaries of the Potomac, must give ample occupation to that canal, as those of New York do to Erie, and as Pennsylvania must to those formed by this state, it will be found that more must be done; that the system of communication will be incomplete until Philadelphia draws her supplies of merchandise from New York, by the facility of a rail-road; and the interior of the States shall reach the wheat market in winter, by a continued rail-road, the whole distance from Carlisle. It is alone by economy of access to market, that the flour of Philadelphia can be afforded as low as will be that of Baltimore. And New Jersey will make her canal, but will not neglect a valuable source of revenue more sure, from a rail-road for winter travel.

The opinion appears to be established, that our country requires a different kind of rail-road from that employed in England. The comparative density of her population, the immensity of her trade, and the moderate extent of her territory, are all contrasted with our widely extended States, and spare population; but while the greatness of our agricultural produce supplies the deficiency in the comparison as to quantity, there remains with us the present disadvanage of great distances, the uncommon length of our public works of this kind. Less expensive modes of construction,

in order that the investments may not be a loss of value in the first hands, seems indispensable.

Various forms of rail-ways have been suggested, and some of them sacrifice durability too much to cheapness. I aim, therefore, to show, how there may be saving enough in capital to allow, besides ample dividends, a reservation from revenue, to form a renovating fund. If this fund is allowed to accumulate at compound interest, rail-roads of a kind suitable to our climate, may be among the best property, because they are not liable to be rivalled, like turnpike-roads, by free roads. Rail-ways cost too much ever to be free; besides, they must have appropriate carriages, owned by the proprietors of the roads, in order that the public may have full accommodation. The public has the same interest with the owners, in there being an ample number of waggons.

Perhaps it will be found that a rail-way of the following description will combine economy with long duration. It will not indeed be elegant, but substantial.

No rail-road can be of long service that is not substantially and accurately made. We may use cheap materials, but the foundations and workmanship must be perfect. In England, they employ much broken stone, for reasons not so applicable to our plan as to theirs. It serves to keep their stone blocks in place, and to fill the trenches in which they rest. But great care is to be taken to form underdrains, and they also take other precautions to keep the earth dry, and consequently hard. We should have occasion to go to more expense for the same object, if it were accomplished effectually. They have only to guard against the effects of one foot of frost in depth, but here it penetrates two or three feet. Ice must not be suffered to form among the foundation, and it must therefore be kept dry. But when our plans and estimates propose an imitation of the English rail-way, how is it that the cost is made to appear less, notwithstanding that the iron and labour here cost double the expense? It is because the ground-work

is not deemed necessary to be so guarded with precautions. Again in this there is danger of saving too much.

Timber is so plentiful in some parts of our country, that nothing seems easier than to have a rail-road, by laying down cross-sleepers, surmounting them with string pieces, and these latter with iron. But how long will it be before the decay of the surface in contact with the ground will disturb its level and parallel, and the travel upon it tear it to pieces? Posts set in the earth, will be more substantial, and they may be guarded at the surface in the following

manner.

It is well known that all posts rot only at, and a little below, the surface of the ground, where heat and moisture combine. Now it has occurred to me, that these two causes of decay may be counteracted, by surrounding those parts of the posts by pavements set in lime, or Roman

cement.

Another mode proposed to save expense, is recommended for the Boston and Providence route. It is that of long stones set edgeways on broken stone, to receive a plate-rail. But besides the difficulty of fastening iron to stone, this plan places the rails too near the surface, and subjects them to be covered with ice. The foundation must also be rammed equally solid throughout, or otherwise the passing of four ton loads will depress the string-stone where least supported. It has, besides, more liabilities to derangements than posts, and cannot cause much saving, if the requisite drainage is properly done.

Perhaps the cheapest plan, consistent with firmness, is the following. Let the object be to make as much of the road permanent as can be done at an ordinary expense. Let embankments be made solid at once, by puddling them. Where wood is used for posts or piles, let them be protected with the cemented pavement, be set in puddle filled with stones, and their heads be also protected; or, instead of broken stone and stone blocks, set rough stone posts, three feet in width, and one foot out of the ground;

their heads being hewn smooth, and also drilled, to receive a treenail in each, with which to secure the bearing timbers together and firmly down at once.

If the bearing timbers are of chesnut, they will be very durable, if split or sawed from the heart of the tree to its circumference; because quarters or eighths of the tree, thus prepared, will shrink equally, and not crack. Being also lodged upon the heads of stone posts, they will not decay at the parts in contact; the horizontal scarps should have their surfaces separated by the intermediation of a cement formed of lime and pitch, a composition used by shipwrights.

The form of the timber allows the heart angle to be placed uppermost, and to be taken off, and a surface formed thereon of three inches in width, for the reception of the rail. A tree of two feet in diameter, will afford eight pieces, of nine inches in depth, and with a base of nine inches; and these dimensions, if the posts are even tenfeet apart, will be sufficient to bear loads of four tons, and also be of sufficient lateral stiffness.

The upper surface of the bearer is liable to be heated by the iron while exposed to the sun, and to shrink and crack. To prevent this, the plate may be put on with screw-bolts, reaching through, with washers and screw-nuts below; but to give the rail a firm bearing, and allow the cement of lime and pitch placed under the plate to remain, two rows of inch nails, and an inch apart every way, may be driven evenly with the surface of the wood; and then, if the upper surface of the plate is convex, the wheels will run along the middle, and the pressure be equal. The passing load will not have a tendency to loosen this rail, as if it was made flat, for a flat rail cannot be mathematically a true plane.

The modes of crossing roads, rivers, &c., are not essentially changed by this plan.

The carriage requires a rather minute description to be understood by those to whom it is now for the first time presented.

If a rail-way is formed firm, smooth, and level, the resistance to be overcome is only friction at the axles, and gravitation, when the load is ascending. The latter being a uniform force, when resisting the ascent of carriages and their load, its ratio, according to the height of the plane, is alike applicable to the old and the new waggon. Friction must ever exist, however lessened by the polish of surfaces, and the use of oil, in proportion to the weight pressing them together. The experiments of Vince proved it to be a uniformly retarding force; those of Colomb, that velocity, increasing in geometrical progression, only increased it in arithmetical progression. And we have, you well know, the experiments of Emerson to prove the proportion of power to weight, when metals of different kinds move on each other. It seems agreed, that iron and brass require one-fifth.

But when the surfaces in question are those of an axle, and the nave of its wheel, the friction is placed under circumstances to be overcome by the augmented power of the lever, that of the second class, which, of course, common wheels are well known to be.

The mechanical ingenuity of England, appears to have been directed to the perfection of the rail-road and engines; the carriage had received no farther improvement than good workmanship. This had achieved the important advantage of reducing the power, according to general practice, to the one hundred and seventy-fifth part of the load.

In this stage of the art, Mr. Winans conceived the idea of combining in one carriage, the first as well as the second classes of the lever. The effect of friction rollers, and friction wheels in machinery, were, no doubt, as familiar to his, as to other minds; but to make a convenient carriage by this combination, principally for rail-roads, then only beginning to be thought of in our country, was worthy of any mind familiar with mechanical science, and practised in ingenuity. It was not, until some time had elapsed, that, in 1826, he presented his first model at the Patent Office,