The exit of the pipes being carried below the level of the furnace, is in preference to cocks, or such like contrivances, in conjunction with regulating apparatus. F F are two circulating tubes, by which the annular space round the furnace is more uniformly supplied with water. G, a pipe with its valves, through which the supply of water to the boiler is injected, to replace the quantity evaporated. H the injecting pump for supplying the bailer widi water ; I, the blowing apparatus, for injecting thearetpiisite quantity of atmospheric air into the furnace. K, a pipe through which the atmospheric air is injected into the casing L, which surrounds the ash-pit, between which a commmication is formed by perforations in the lower part of the cylinder which constitutes the furnace • the blast is by this means rendered less partial in its action on the fuel . To one extremity of the pipe K is attached a regulating valve or cover M, which, when dosed, prevents the exit of the air contained in the pipe,—the quantity of air discharged through this aperture depends on the area of the opening given to the valve. It is opened or shut, or otherwise adjusted, by means of a screw and handle, or may be operated upon by any other conve nient means. This valve is used for regulating the quantity of atmospheric air passed through the furnace, suited to all the variations of resistance. To the other extremity of the pipe X is adapted a hinged valve or cover N, so weighted as to counterpoise the pressure of the air within ; the pipe, when dosed, compels the air discharged by the blowing apparatus to pea into the cuing L, and from thence into the furnace, through the flue-pipes E E, &c., into the atmosphere, excepting that quantity which may be discharged through the valve M. The use of this valve is to limit the temperature cf the water, and consequently the pressure of the steam in the boiler, by permitting, when open, the discharge of a at portion of the atmospheric sir otherwise requited for combustion. To effect this object, the valve N is connected by levers 0 P Q, with their necessary rods of communication, to the calorific regulating apparatus R, which consists of a piston of sufficient area to overstate the resistance opposed to it, working through a stuffing-box in a cylindrical syphon tube, con taining a quantity of mercury as a medium by which the steam, passing from the boiler into the regulating chamber, acts upon the aforesaid piston. S, a safety-valve, with its graduated lever and wsaght ; a loop T is formed on the end of the lever, and embraces the screwed end of the regulator piston; when the nut V comes in contact with the loop, the lever and safety-valve are lifted effectually, preventing the occurrence of accidents, should the safety-valve remain closed beyond the limiting pressure. The action of the safety-valve and lever is tendered simultaneous by two small connecting links. At X is a chamber attached to the crown of the furnace, and connected by a tube Y, with a piston and cylinder of precisely the same description and construction as that used for the calorific regulator R, and may be placed in any convenient situa tion for operating on a safety slide cock or valve Z, which, when the water in the boiler has evaporated so low as to endanger its safety from a deficiency of supply from the force-pump, is closed, and completely prevents the pussy of atmospheric air into the furnace—thus combustion instantly ceases, the ignited fuel being deprived of air. The motion communicated to the piston by the steam generated in the chamber X, operates on the levers shown, until the ver tical lever rising with the piston, he detent passes the projecting fin, when the slide Z is instantaneously released, and falls by its own gravity, completely closing the passage through the pipe K. The combustion being impended, the temperature of the water, and consequently the pressure of the steam, is instantly reduced, thus preventing the destruction of the boiler by the powerfel action of the fuel when the heating surface is unprotected by the water. For facilitating the reference, the regulators R are arranged with a view to perspi cuity, rather than mechanical exactness. It will be perceived that the safety slide Z with its appendages, have been omitted in Pig. 1, lest it should have been rendered too confused. The steam cylinder, piston, and stuffing-boxes, being of the usual construction, do not require a particular description, the only peculiarity being the great length of the cylinder compared with its diameter, and the small diameter of the piston rod. The adjustment of the piston in the cylinder I. effected by means of screws and nuts at the two extre mities, where they are connected to the chains a s by the loops r r. The slide yalves a a are connected together by two adjusting side rods 66, and have two apertures each, with a connecting chamber c The seats have each three aper tures, of equal area with those in the elide, so that the alternate operation of admit ting steam to the cylinder, and condensing it, is produced without the aid of a casing or cover over the slide. The movement producing the alternating motion of the slides, is of the tappet kind, capable of the nicest adjustment, by means of screws and nuts at each end of the tappet rods dd, which also connect them with the chains. a is a carriage fir supporting the tappet lever f, and the guide rollers g g, against which the tappet rods rub, and by which they are prevented from deflecting out of the right line when brought into action. The side rods b b are united at A, the middle of their length, by a carriage furnished with friction rollers, which is embraced by the forked ends of the tappet rods f, and by which the elides are moved. The pressure tending to lift the slides from i their seats by the action of the steam in their passages, is counterbalanced by an external pressure produced by two helical springs k k, at the back of each slide, and the friction is diminished by two grooved rollers LI, working on a guide parallel to the face of the slide. in is the condensing chamber, into which the steam is admitted after it has performed its office in the cylinder, where it is permitted to expand freely. The slide valve seats communicate with the upper part by the pipes n a which enter the chamber separately, or united in one pipe. The water produced by the condensation of the steam is drawn from the chamber by the force-pump H through the. pipe and valves o, which chamber is furnished with an inverted safety-valve p to prevent collapsing. The steam is completely excluded from the engine by dosing the slide valve q. The chains as are fixed to the pulleys t t, whose axes turn in bearings on the bracket v v, firmly secured to die transverse bearers of the frame work of the carriage. These pulleys should be more in circumference than double the length of the piston's stroke. The reciprocating motion of the pulley t and the engine, pro duce the revolution or rotation of the crank shaft W, by means of a lever keyed on one end of the pulley axis, and the intervention of the connected rod y, the crank shaft revolving in bearings attached to the frame of the carriage. The radius of the lever must exceed in a trifling degree that of the crank so sr. is, a
toothed spur•wheel working into a pinion of half its diameter on the axis of the carriage-wheels 5, so that the carriage performs a distance equal to twice the circumference of the wheels 5 for each double stroke of the engine. Any other proportions of the wheel andpinion may of course be adopted as the nature of' the machine or the required speed of the carriage may render neces sary. On the crank shaft W is a pulley 8 grooved, to receive a catgut band for the purpose of driving the machinery to work the blowing apparatus. These wheels 3 and pulley 6, have been represented by dotted lines to prevent con fusion. The machinery for working the blowing apparatus consists of two pulleys 7 on an axis 8, supported on two brackets 9 fixed to the side frames of the carriage ; one pulley to receive the motion from the crank shaft W, and the other to communicate the motion to the pulley 10. On the axis of the blowing fan a greater number of pulleys may be found convenient to vary the velocity of the blowing fan, according to circumstances. The pulley axis 8 is cranked, to form a winch by which the blowing apparatus can be worked by manual labour, where the engine is at rest, and for which purpose a provision is made to disengage the pulley from the crank shaft W, by Aiding the brass bear ings in the bracket heads in the direction of the crank shaft. The catgut band will then be slackened, and the pulley will revolve without it; when it is required to be connected with the engine, the reverse of this operation will be necessary, in either of which positions, the axis will be retained by a set screw 11. The force pump is worked by means of an adjusting crank 12, keyed on one end of the axis of the pulley 4 and communicating with the pump piston by a con necting rod and slings 13. The pump is secured to a portion of the bracket v, projecting below the carriage frame.
To avoid the impediment that is likely to occur occasionally from snow or ice upon railways, Mr. Grime, of Bury, has proposed, under a patent right, dated the 21st February, 1831, to dissolve the same by making the rails hollow, and causing hot water, steam, or hot air, to pass through them, so as to keep them at a temperature above the freezing point. For this purpose a boiler is to be erected by the side of the railroad, at distances of two or three miles from each other. One of these boilers being supplied with water, and heat applied, the water is forced, by the pressure of steam on its surface, through a pipe communicating with the hollow rail, and reaching nearly to the bottom of the boiler, and along the railway, till it ceases to give out a sufficient quan tity of heat to melt the snow or ice which may lodge on the rails, when the water is received into another boiler by means of a feeding vessel placed over it. This feeding vessel is connected with the boiler by two pipes,—the one descending from its bottom to very nearly the bottom of the boiler, to form a water communication, and the other from its top to the top of the boiler, to form a steam communication. Each of these communications is provided with a stop-cock and levers, from both of which, as well as one from a cock on the pipe which supplies the feeding vessel, are connected with a float in the boiler, by means of a wire passing through a stuffing-box, in a manner similar to that in Eng. Ency. Vol. I. p.216, where the float descends by the escape of water through the exit pipe into the rails : the steam and water communication from the feeding vessel to the boiler are thereby opened, while the supply pipe to the feeding vessel is closed, when the water contained therein is forced, by the pressure of steam on its surface, into the boiler, till the float is elevated so as to close the communications between the feeding vessel and the boiler, and to open that between it and the hollow rails, for the admission of a fresh supply of cooled water.
It is stated in the specification, that instead of the hollow rails, hot water pipes may be laid along the line of road, in contact with rails of the usual con struction. The lengths of hollow rail are connected together by pieces of copper pipes fitting accurately into the ends of the pieces of hollow rails, which they unite, leaving a space between them sufficient to allow of their expansion by the increased temperature.
On the 2d August, 1831, a patent was granted to Sir James C. Anderson, Bart. of Buttevant Castle, Ireland, for a very judicious arrangement of me chanism for propelling carriages by manual labour. This gentleman designed a carriage, in which as many as twenty-four men were arranged on seats, in the manner of rowers in a boat, but in two tiers, one above the other ; the action was nearly the same as the pulling of oars, the only difference being, that by Sir James's plan, all the men sitting on one seat pulled at one horizontal cross bar, each extremity of which was flirnished with an anti-friction roller, that ran between guide rails on the opposite sides of the carriage. The ends of each of these horizontal bars were connected to reciprocating rods, that gave motion to a crank shaft, on which were mounted spur gear, that actuated similar gear on the axis of the running wheels of the carriage; so that by sliding the gear on the axis of the latter, any required velocity could be communicated to the carriage, or a sudden stop made. A carriage of this kind it was proposed to employ as a drag, to draw one or more carriages containing passengers after it. The worthy Baronet informed us, that he had chiefly in view the movement of troops by this method, which would enable them to effect their marches with greater facility and despatch ; hence he justly considered that there might be a great diminution of the peace establishment, without detriment to the service.
Mr. Alexander Gordon, in his Treatise before referred to, disapproves of all attempts at "homo-locomotion," except the use of his legs, experience having proved, in his opinion, the utter vanity, if not impiety, of all propositions of the kind. He instances the Velocipede as the most promising of' all; yet a failure! Hence he deduces, that "the inexplicable vital principle bestowed by the omni potent God upon his creatures cannot be superseded by man's utmost know ledge in mechanical science." In our simple opinion of the matter, Mr. Gordon has entirely overlooked the obvious fact, that whatever mechanical improvement may be erected by the "creature," it must necessarily proceed from the Creator. Admitting, however, for mere argument's sake, that the Velocipede was a failure upon the common road, does it not follow that upon a railway, where the resis tance to motion is only a fifteenth part of the former, that the effect would be vastly increased by the exertion of the same motive force? And although the railway is one of the results of our increased knowledge, we are far from believing that Messrs. Stephenson and Booth have yet attained the " utmost knowledge in mechanical science " that man is capable of; or that the Omnipotent may not vouchsafe to man such an increase of his capabilities, as will cause the present age to be hereafter regarded as one of comparative iarkness.