The annexed figure represents a ground plan of the wheel w w of a self-acting inclined plane, round the rim of which the rope winds, by which the loaded carriages drag the empty ones up the plane. The wheel is generally of cast-iron, about six feet diameter, with six spokes, and a grooved rim for the rope to wind upon, the groove being only of sufficient width to hold the rope within it as the wheel moves round ; consequently the rope, when in action, only round one half of the wheeel, from a to passes round the top of the plane, a square hole is dug, the sides of which are lined with masonry, the top being nearly upon the same level as the railroad; the wheel then placed between two frames of timber, the upper of which, a b and c d are shown in the drawing. They are kept steady by the diagonal braces e e. The carriages on which the axle runs are placed on the front of these frames ; the upper one at g, and the other immediately below it, on which the ends of the axle that sustains the wheel rest, and on which it is at liberty to run freely round. At the top of the inclined plane, a certain space of ground, for about twenty or thirty yards, (varying accor ding to the number of carriages run down at a time,) is made nearly level, on which the loaded carriages remain until they are to be lowered down, and on which the empty ones stop after their passage up the filane; at the end of this level, or slightly inclining ground, furthest, from the top of the plane, the wheel is placed, and small horizontal sheaves sate 8 8 are placed in the direction the rope runs, to prevent its being injured by dragging along the ground, and also to diminish its friction. These horizontal sheevea are placed at inter vals of every eight or ten yards upon the plane from one end to the other. The draw ing will show the periphery of two kinds; the one being flat, and the other circular, and of a width just sufficient to admit the rope upon it; their diameter about eleven inches, with a flange on each side to prevent the rope from running off: they are made most frequently to run upon pieces of wood, and sometimes upon cast-iron stands, placed upright upon the middle of the road ; the axles are made of wrought-iron, and where they rim upon the upright bearings, about three quarters of an inch diameter. The plane is then made into a proper slope, between the platform or level upon which the wheel is placed, and the lower extremity, when a similar fiat or piece of level road is made, for the descending train of waggons to land upon. The slope h either uniform, or such as the nature of the ground will permit. Some times it is necessary to make considerable bends or curves in the line of the road; but whatever be the form or length of the slope, it must always be termi nated at each end by these flat platforms. The narrow parallel lines in the drawing, will show the rails as laid down upon the platform ; the wheel being placed below the level of the rail, the spiare hole is covered up, and the rails pass over upon the cover. In the drawmg, the rails are broken off at k k, the cover being removed to show the wheel. The dotted line A A, may be supposed to represent the one end of the platform, and the top of the plane. Three rails r r r are laid froin this part nearly half way down the plane, of the requisite width between each rail, for the carriages to run upon, so that both the ascend ing and descending train pass upon the middle, and upon one of the outer rails ; these are continued to where the one train of waggons have to pass each other. The three rails, then made to branch into four, in the same man ner as A A to B B, for a certain distance, sufficient to allow the carriages to pass each other; these four rails then converge into two, or a single line of road, as shown at c c, and are so continued to the bottom of the plane, so that parallel lines, as shown in the drawing, will represent a complete passing. The empty, or ascending carriages will be at c c when the loaded carriages are at A A, and they will pass each other between K and B B'. In this form of plane, it will be seen, that the loaded carriages pass alternately down the sides D and E. For instance, if they commence their descent at D, one end of the rope being attached to them, and the other end being at E, at the foot of the plane, and fastened to the empty carriages, the loaded carriages will pass down D, and when they arrive at the bottom, the empty ones will arrive at the top, at E. Upon the other side of the plane, the loaded carriages, in the next operation, pass down the side E of the plane, and the empty ones up D. When used for passing boats from one level to another upon canals, and also on several railroads, a double line of road is laid from top to bottom of the plane, with a double line of rollers or sheeves; but the reader will perceive, that in most cases, the one above described will answer precisely the same purpose. In very short planes the obliquity of the road, in passing from a double to a single line, will cause a retardation to the carnage', and also additional friction to the rope ; but upon long planes this is scarcely felt, and the cost of a double_ road the whole distance would be considerably greater.
When the slope of the plane is not uniform, descending more rapidly in some parts than in others, or when the descent is so great as to give more than a requisite preponderance to the moving power, a brake is applied to the peri phery of the inclhied wheel, to equalize or regulate the velocity of the carnagee down the plane; and, in many instances, men traverse the plane with each train of waggons, and apply the brake or convoy of the carriages to check their velocity, when required. The brake upon the inclined wheel will be w ceived to have no power in checking the velocity of the carriages more than what is equal to the hold the rope takes upon the wheel in passing round its semi-periphery ; for if the excess of gravity of the loaded carrisges, above what is required to overcome the whole retarding forces, be greater than the hold of the rope, the wheel may be completely stopped, and the rope slide round the wheel, which in some instances, might be attended with danger. The decli vity of the plane should never be so great as to cause such an excess or pre ponderance of gravity, when such a wheel as this is used.
Many other plans have been suggested for employing rarity as a moving power. With a view of improving upon the various contrivances for surmount ing the natural difficulties of a hilly country, Mr. Benjamin Thompson, late of Ayton, Durham, took out a patent dated October 24, 1821, for "a method of facilitating the conveyance of carriages along iron and wood railways, tramway', and other roads;" in the specification of which, he states, that it consists in the application or use of two, or more, fixed engines, placed upon the way, or other road to be used, at such a distance from each other as the nature of the line chosen shall render most convenient, and in such a manner as that the action of such engines shall be able and reciprocal. Mr. Thompson says, that " ther the line of road rises or falls, much or little, is level or undulating, matters not ; the carriages, loaden and empty, are made to pass in both directions with a uniformity of progress, and at the same time with a despatch not heretofore known. A road on which my invention is about to be applied, must be divided into stages, attention being given, in determining their tances, to the nature of the line, in regard to curves or bends, and to the undulation of the surface. The nearer it approaches to a level, and the fewer, as also the easier, the bends are, the better will it allow of the stages being extended. On the other hand, should the line prove to be a very uneven one, with frequent and short bends, then the intervals or spaces between stage and stage will necessarily be required to be shortened accordingly. I shall probably be able more clearly to explain my method by describing a supposed case. Let the supposed road, to which my invention is to be applied, be a railway (either already in being, or to be made,) from a colliery to a staith, seven and a quarter miles in length. A. proper survey being taken, and a plan and section of the line made, I find it to be expedient to divide it into five stages, in the manner shown by the drawing annexed. The first stage of the colliery may be formed to a tolerably uniform ascent, by the aide of cuts and batteries, of one and half inch to the yard, being three-quarters of a mile in length, and terminating at a summit, on which is to be erected a steam-engine, of power sufficient to draw up the plane six loaden coal waggons at once, containing a Newcastle chaldron each, at the rate of seven and a half feet per second. This stage is a regular inclined plane, and is to be wrought according to the first of the modes already described as now in use ; for the returning empty waggons will pass downward by their own gravity, and take the rope with them, preparatory to the drawing up of another loaden set. The full set being drawn up in eight minutes and eight seconds, the empty set allowed to pass down in seven minutes and eighteen seconds, and three minutes occupied in the changes at the ends, will cause one operation of the plane to be completed in nineteen minutes and six seconds. The engine which I call
No. 1 is the first station. The second stage lies over a variable or undulating surface, the two extremities of which are distant one mile and three-quarters, and stand nearly level with each other, the intermediate country not admitting, but at too great a cost, of the line being rendered level ; the ascents and declivities are moderate, neither exceeding one inch in the yard ; and the curves or bends are easy, and not numerous. A steam-engine, No. 2, is erected at the farther termination, which is the second station, to be used for drawing twelve loaden waggons along this stage at once at the rate of eight and three-quarters feet per second, and bringing along with them a rope from No. 1 engine, which is allowed to run off a wheel, not connected with No. 1 engine, during their passage to No. 2 engine ; upon their arrival at which, twelve empty waggons are substituted, which are drawn back to No. 1 by the reconnexion of the rope-wheel with that engine, bringing with them a rope from No. 2 engine, which is, in like manner, suffered to run off a wheel, then thrown out of connexion with No. 2 engine. The operation of this stage, both from and towards the colliery, is thus carried on by the alternate action of Nos. 1 and 2 engines, standing at its extremities. The passage of a set of waggons takes up seventeen minutes and thirty-six seconds each way, and the changes three minutes ; making together, for a completion of the operation, thirty-eight minutes and twelve seconds, or double the time taken by a set of half the number on the first stage. The third stage is also one mile and three-quarters long, and very similar in regard to plan and section to the second stage. A steam-engine, No. 3, is placed at the third station, which is the furthest extremity of the stage, to draw the loaden waggons along the same; and the empty ones are to be taken back by No. 2 engine, in the manner which has just been described on the second stage. The speed, and the number of waggons to a set, are the same also. The fourth stage is more favourable than the second and third, extending over a gently undulating country, and being nearly straight; the fourth station, or further extremity of the stage, being, in point of level, twenty feet higher than the other end of it. A steam-engine, No. 4, is to stand at the fourth station, to be used for drawing the waggons from the third station. Nos. 3 and 4 engines will thus alternately act to each other on this stage, as Nos. 1 and 2 have been described to reciprocate on the second stage, and also Nos. 2 and 3 on the third stage. The length of this stage is two miles ; and twelve waggons are to travel together, at the rate of ten feet per second, which will complete the process of a passage each way, with the changes, in thirty-eight minutes and twelve seconds. The fifth and last stage, which is one mile long, declines regularly by the help of cuts and batteries, to the staith, averaging three-quarters of an inch to the yard. The loaden waggons are made to pass down the same, in connexion with the machinery of No. 4 engine, and also during the time of its drawing a set of full waggons along the fourth stage; the waggons along the fifth stage moving with half the velocity of the waggons along the fourth stage, or five feet per second, and consequently performing the journey in the same time. The advantages of this cooperative movement are, that No. 4 engine, being aided by the gravity of the twelve loaden waggons passing down the inclined plane to the staith, requires only about one half the power which otherwise would have been necessary for drawing independently the full waggons from the third station, and the descending waggons themselves are restrained from proceeding too rapidly, and their speed accurately The engine No. 4 is used to draw the empty waggons back again from the staith. This mode, whereby the gravity of the loaden waggons passing down an inclined plane is applied in aid of an engine for drawing loaden waggons forward upon another stage, is quite new, and has never been used before ; but I do not claim it as any part of my said invention. The second, third, and fourth stages, are those on which my method is applied. Nos. 1 and 2 engines reciprocate, or act interchangeably with each other on the second stage; No. 2 drawing the loaden waggons from the first to the second station, and No. 1 pulling the empty (or in case of need, loaden) waggons back again. Engines Nos. 2 and 3 operate alternately in the same manner with each other upon the third stage ; and so also do Nos. 3 and 4 on the fourth stage. The engines are severally to be furnished with two rope wheels, and a rope to each, of a length and strength suitable to the stage upon which they are to be used. The rope-wheels must be so constructed as to allow of a ready connexion, or the contrary, with their respective engines, so as to be capable of being acted upon by them, or of turning round, independently, at the will of the engine man. This may be readily accomplished by any one of the modes in use with mill-wrighta for throwing machinery into or out of Beer, with a moving power, and does not require to be here described. I make use of very light friction-wheels, a b c d, &c. in the drawing, placed vertically, at proper in tervals, to bear the ropes from the ground, where the road is straight; and round the curves or bends I place similar wheels, in inclined positions, for the same purpose. Although two miles have been mentioned as the longest of the stages upon the supposed road, it is practicable, under the circumstances of a favourable country, to extend the operation to much longer stages. Without the applica tion of my invention to the supposed road, of which a detailed account has been given, horses would be required to draw the waggons upon the second and third stages, because the ascent of one inch to the yard is too great for locomotive engines to be used upon them, independent of the question as to their effecting a saving at all upon horse labour, on those level roads where they are applicable. Upon the fourth, or two mile stage, they might be adopted; but, from the doubt as to an advantage under any circumstances arising by their use, horses would most likely be deemed the more eligible for working it also. Compared with horse labour, my method would, upon those three stages, effect, in all proba bility, a saving of seventy-five per cent. In cases of greater inequality of sur face, the saving would be in a still greater ratio. A further and very important reduction in the cost of a new road, would result from its adoption. In the formation of a road, it is generally necessary to make deep cuts, and raise high batteries, in order to obtain a uniformly rising, falling, or level surface ; and it frequently happens, too, that the direct line of way must be materially diverged from, to favour that purpose. My plan dispenses with such nice attention to regularity, the engines being capable of surmounting acclivities, and the wheels which give out the following or passive rope, affording the means of restraining the too rapid progress of a waggon down a declivity. In short, there is no country, however uneven or variable its surface, but that may, by my method, be traversed. For conveying minerals underground, whet. the unevenness of the strata and their general disposition to undulation do not allow of a uniformly ascending, descending, or level road, my invention is peculiarly applicable. Briefly, then, and it will easily be collected from what has been said, My method of facilitating the conveyance of carriages along iron and wood rail ways, tramways, and other roads,' is the reciprocal action of two engines, stand ing at the extremities of a stage, or portion of road to be travelled over, one engine drawing the- carriages forward in a direction towards itself, and along with them a rope from the other engine; which rope, in its turn, pulls the same or other waggons, by means of the other engine, back again, and also a rope therewith—thus, by the alternately active and passive agency of two ropes, are the powers of fixed engines made to act in opposite directions, thereby causing a road to be traversed both ways, by loaden or empty carriages, at any desired speed. It is the reciprocal and interchangeable application of power, as hath been described, which I claim to be my invention.' The inventor had an opportunity of putting his plan into execution, imme diately after the sealing of his patent, at Ouston colliery, in the county of Durham, and about seven miles from Newcastle, upon a length of line of seven and a quarter miles, as in the supposed case mentioned in the specification. The principle was, however, at that time only applied through the medium of two steam-engines, previously used in drawing loaden waggons up inclined planes.