The second head of invention under the patent is of a more singular charac ter, and however preposterous it may at first appear to those who have not con sidered the subject, it is in reality by no means absurd in principle, nor in the rationale of the proposition; but we will first describe it, and afterwards make our observations.
Instead of placing horses outside of a carriage to give it motion, the patentee puts them bustle for that purpose ; and his reason for doing this, that of in creasing :the force nr velocity, will to many appear to be quite as paradoxical. The above Fig. 1 affords a perspective view of a machine of the kind, end Fig. 2 a section of the wheel-way and mechanism by which the process of pro pulsion is effected. This second part of the patent is thus described in the Register of Arts :—" b b represents a vertical section of the road in which an excavation is made, and the ground well rammed, so as to lay down, at uniform distances, a series of cast-iron frames or sleepers c c. In the several partitions of the sleepers are placed, lengthways, four lines of timber. The two prin cipal rails, d d, are of oak, and stand about three inches above the level of the other parts. The other two lines of timber, e e, are three-inch planks, set on edge, and bolted to the framing. Resting upon these deal planks and the iron partitions, and flush with the oak timber, are laid, crossways of the road, short pieces of three-inch oak plank, leaving an open crevice about one inch and a half wide between them. These short planks are laid edge to edge, uniformly along the whole line, so as to form a level floor, over which is screwed down a complete covering of wrought-iron plates, a a. On this hard and level surface, the wheels of the carriage are intended to roll. Inside the hollow trunk is the mechanical horse, which is actuated by motive force applied above, through the medium of similar gear to the before-described. Only two-toothed wheels are shown in the trunk ; there is, however, another, which cannot be seen in this view, which, when put into fear with the opposite rack, reverses the rota tory motion, and causes the carriage to proceed in the same direction. The lowest wheel of tie three shown is made light, as it only operates as an antifriction roller, and for that reason occupies the whole space between the two three inch deals. The perspective sketch in Fig. 1, though rather dispro portioned in some of its parts, exhibits a carriage of the kind described in the specification. It consists of two stories,—the upper one for passengers, containing both inside and outside berths; and the lower one for merchan dise, which is deposited on a circular floor, around which two horses are made to work, as in a mill, being yoked to the two opposite extremities of a horizontal lever, that turns a vertical axis, to which is connected multiplying gear that causes the mechanical horse in the hollow trough, and the car riage above, to move at any predetermined velocity of motion; the horses, however, continuing to move at that slow pace (of about 21 miles per hour), hy which they can most efficiently exert their force. The diagram marked
..Pw. 2 is explanatory of these motions : g g are two yokes, to which the horses, being attached, give motion to the horizontal lever and the vertical shaft h, on which is also fixed, close under the floor of the carriage, a large hori zontal spur-wheel i; the revolution of this wheel actuates a pinion j, which pinion being on the same spindle as the toothed wheel on the mechanical horse, which takes into the rack, causes the carriage to advance at about four times the velocity of the horses, or at ten miles an hour. Mr. Snowden calculates the power of an average horse, in drawing a load, at the rate of 2i miles per hour, for four hours a day, as equal to the constant force of a weight of 250 pounds, when drawing in a straight line : if the speed of the horse be or in creased to 5 miles per hour, his power of traction will be reduced to only 50 pounds ; and if the speed be again doubled, or made 10 miles per hour, the horse can do no work whatever, except through only a very short space of time. The slow motion, therefore, is by far the most favourable mode of applying the power of a horse; and although the contracted circuit of a mill-walk is un favourable to the full exertion of his powers, Mr. Snowden estimates that a force of about 200 pounds may thus be obtained. Of this available force he pro poses to sacrifice three fourths, by means of multiplying gear, into velocity ; and thus enable each horse to give out, in effect, a force of 50 pounds at 10 miles per hour ; whereas, if the horses were to move themselves at that velocity, they would be totally ineffective. If, therefore, we consider two horses to bestow a force of 100 pounds, and that the resistance on the patentee's wheel way is no more than that of the Manchester and Liverpool railway, namely, 1 in 240, we have 100 x 240 = 24000 lbs. propelled by two horses, at the rate of 10 miles an hour. But the friction of such machinery must be considerably more than I in 240, and the above-estimated force of a horse moving in a circle of 16 feet diameter, is probably much too high. Let us therefore suppose the usefill effect to be only half, reducing it to 120001bs. The popular objection to this plan, is the apparent absurdity of the horse having to carry his own weight ; but this objection equally applies to the steam engine, or any other locomotive power : the whole question, however, resolves itself into one of convenience and economy, as applied to particular cases and circumstances, which we can not here discuss ; and as we shall have occasion, in our account of Brandreth's Cyclopede, to notice the subject again, we shall here conclude with the remark, that we believe it is worthy of the consideration of the machinist to devise the most perfect locomotive machinery, for converting the force of a horse at a slow motion, into a higher velocity with a diminished force.