point we are amusingly informed by Dr. Lardner (Treatise, p. 255), "This method was perfectly effectual; and although its practical application was found to be attended with difficulty in the hands of common workmen, Mr. Gurney was persuaded to adhere to it by the late Dr. Wollaston, until experience proved the impossibility of getting it effectually performed, under the circumstances in which boilers are commonly used. Mr. Gurney then adopted a method of removing it by mechanical means. Opposite the mouths of the tubes, on the other side of the cylinders, are placed a number of holes, which, when the boiler is in use, are stopped by pieces of metal screwed into them. When the tubes require to be cleaned, these stoppers are removed, and an iron scraper is introduced through the holes into the tubes, which, being passed backwards and forwards, removes the deposit." This extract proves that Mr. Gurney not only abandoned his " tubes bent into peculiar curves," but likewise the "chemical solvent," which constituted his second and sixth claims. The seventh claim is for "an apparatus for regularly supplying the boiler with water," which was to be done by the familiar yet exploded mode of working simultaneously by a connecting rod, two cocks situated on the opposite ends of a water reservoir.

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Having thus waded through, as quickly as possible, the materia as well as the medica of this "happy series of inventions, as they were denominated by a celebrated writer in the Times Newspaper, it is natural to inquire what became of them. Hitherto we have never met with, nor ever heard of, a single contrivance of Mr. Gurney's that was ever brought into permanent use, or had the slightest effect in advancing or improving the art of steam locomotion. It is unquestionable that many steam-carriages were built under his orders; but so have many more been built, before and afterwards, by the expenditure of less money. We have seen what Mr. Gurney has claimed for himself in his specifications; that most of them were of too puerile and absurd a character to deserve even a trial; and that the remainder were notoriously long before his time publicly in use. Surely a man who could descend to such gross quackery would not have omitted to claim something really beneficial in locomotion, had he invented it. The inference is unavoidable,-that Mr. Gurney had no more to do with the invention of steam-carriages, than he had with the building of St. Paul's Cathedral. After the expenditure of many thousands of pounds, he brought out one of his manufacture, towards the close, we believe, of the year 1827. We shall annex a popular description of this carriage, which is extracted from a weekly journal published at that time.

"The carriage is constructed for accommodating six inside and fifteen outside passengers, independently of the guide, who is also the engineer. In front of the coach is a very capacious boot, while behind, that which assumes the appearance of a boot, is the case for the boiler and the furnace, from which no inconvenience is experienced by the outside passenger, although, in cold weather, a certain degree of heat may be obtained, if required. The length of the vehicle, from end to end, is 15 feet, and, with the pole and pilot wheels, 20 feet. The diameter of the hind wheels is 5 feet; of the front wheels, 3 feet 9 inches; and of the pilot wheels, 3 feet. There is a treble perch, by which the machinery is supported, and beneath which two propellers, in going up a hill, may be set in motion, somewhat similar to the action of a horse's legs under similar circumstances, which assist in forcing the carriage to the summit. "In descending a hill, there is a break fixed on the hind wheel, to increase the friction; but, independently of this, the guide has the power of lessening the force of the steam to any extent, by means of the lever at his right hand, which operates npon the throttle valve, and by which he may stop the action of the steam altogether, and effect a counter vacuum in the cylinders. By this means also he regulates the rate of progress on the road. There is another lever by which he can stop the vehicle instanter, and in a moment reverse the motion of the wheels, so as to prevent accident, as is the practice with the paddles of steam-vesssels. The duty of the guide, who sits in front, is to keep the vehicle in its proper course, which he does by means of the pilot wheels acting upon the pole.

"The total weight of the carriage and all its apparatus is estimated at one and a half ton, and its wear and tear of the road, as compared with a carriage

drawn by four horses, as one is to six. The engine has a twelve-horse power, but may be increased to sixteen: the actual power in use, except in ascending a hill, is eight horses.

Fig. 1 gives a side view of the machine; a the guide and engineer, to

whom the whole management of the machinery and conduct of the carriage is entrusted. Besides this man, a guard will be employed, whose duty it will be to look after the luggage and passengers; b the handle, which guides the pole and pilot wheels; c the pilot wheels; d the pole; e the fore boot, for luggage; f the throttle valve of the main steam pipe, which, by means of the handle, is opened or closed at pleasure, the power of the steam and the progress of the carriage being thereby regulated, from one to ten or twenty miles per hour; g the tank for water, running from end to end, and the full breadth of the carriage; it will contain sixty gallons of water; h the carriage, painted claret colour, and lined with cloth of the same hue, capable of holding six inside and twelve outside passengers; i the hind boot, containing the boiler and furnace; it is encased with sheet iron, and between the pipes the coke and charcoal are put, the front being closed in the ordinary way (as seen in Fig. 2), with an iron door. The pipes extend from the cylindrical reservoir of water at the bottom, to the cylindrical chamber for steam at the top, forming a succession of lines something like a horse-shoe turned edgeways. The steam enters the separators' through large pipes, and is thence conducted to its proper destination; kk separators, in which the steam is separated from the water, the water descending

and returning to the boiler, while the steam ascends and is forced into the steam pipes of the engine; the pump by which the water is pumped from the tank, by means of a flexible hose, to the reservoir communicating with the boiler; m the main steam pipe descending from the separators,' and proceeding in a direct line under the body of the coach to the throttle valve,' and thence, under the tank, to the cylinders; n n flues of the furnace, four in number; o the perches, of which there are three, conjoined, to support the machinery; p the cylinders

there is one between each perch; q valve motion, admitting steam alternately to each side of the pistons; r cranks operating on the axle; at the ends of the axle are ratchets which, as the axle turns round, catch projecting pieces of iron on the boxes of the wheels, and give them the rotatory motion-the hind wheels only are thus operated upon; s propellers, used as the carriage ascends a hill; the drag, which is applied to increase the friction on the wheel in going down a hill; this is also assisted by diminishing the pressure of the steam, or, if necessary, inverting the motion of the wheels; u the clutch, by which the wheel is sent round; v the safety valve, which regulates the proper pressure of the steam in the pipe; w the orifice for filling the tank; this is done by means of a flexible hose and a funnel, and occupies but a few seconds. Fig. 2 exhibits a back view of the carriage, and the perches that support the machinery, not here introduced; a the furnace door; c gauge cock; d blow cock; ee steam pipes; ff flues to furnace; gg the pipes through which the water is propelled from the separators h h into the boiler.

In October, 1825, Sir George Cayley, of Brompton, in Yorkshire, obtained letters patent for a locomotive apparatus on the same principle as Mr. Barry's, described at page 445, but somewhat differently applied. An elevation of this machine is given in the following cut; a a represent a side view of the fore and hind running wheels of the carriage, the axletrees of which are made fast to the inclined ends of the waggon box b; each of the two pair of wheels have deep grooves cc in their peripheries, and into these a stout endless chain d d is passed around, so as to connect the fore and hind wheels together on the opposite side of the carriage. To show the groove c, one of the wheels is represented with one of the side flanges removed. Each link of the chain carries two perpendicular arms, which serve as the carrier or bearings to a small roller e e, which revolves at right angles to the running wheels. These rollers, which form a continuous series on both sides of the carriage, come successively in contact with the ground as the machine is moved in its course, and step over the obstacles that may lie in their path. But in the case of any of the rollers

alighting on a prominent stone, which might cause an injurious strain upon the machine, a solid wheel or roller f is fixed midway between the wheels on each side of the carriage, which receive and are capable of sustaining the pressure. In order that the carriage may be moved sideways, the rollers are placed at right angles with the running wheels.

The patentee has introduced into his specification some ingenious contrivances for keeping the wheels in a straight path upen unlevel surfaces; but as these

do not possess a very practical character, we must refer the reader to the specification for the particulars of them.

In the early part of this article are given some plans for the employment of toothed racks to railways, to enable a carriage, provided with a toothed wheel, taking into the teeth of the rack, to obtain sufficient resistance to ascend steep inclined planes: but the former were subject to the disadvantage of a strain or twist, the rack in them being placed on one side of the way. To obviate this defect appears to have been the object of Mr. Josiah Easton, who took out a patent, dated the 13th October, 1825, for "certain improvements in locomotive or steam carriages, and also in the manner of constructing the roads or ways for the same to travel on." The following brief description of this invention is given in the London Journal of Arts, Vol. XI.:-"These improvements consist, first, in forming a line of road, with a raised part along the middle, upon which a rack, or toothed bar of iron is placed; and secondly, in adapting a toothed wheel to the steam carriage, which shall take into the said rack, and being actuated by the rotatory power of the steam-engine, shall thereby cause the carriage to be impelled forward upon the line of railroad, and the trams or other waggons after it."

Fig. 1.

In the subjoined cuts, Fig. 1 exhibits a transverse section of the railroad, with the end view of a waggon upon it. Fig. 2 is a side elevation of the same, showing the manner in which the carriage is driven; a a is the road formed of masonry, the parts bb, on which the running wheels travel, being on a lower plane than the central part c of the road, whereon the rack d is situated. The steam-engine, and other machinery appertaining to the locomotive, are constructed in the usual way; the only novelty in the carriage is the toothed wheel e, which takes into the rack d, fixed along the centre of the road; and this toothed wheel being made to turn through the agency of a train of wheels actuated by the steam-engine, the carriage is thereby propelled, and the waggons drawn after it. In order to keep the carriag s in their track upon the road, two guide rollers fƒ are placed under the carriage, which run against the side of the central rib, and this prevents them from moving out of their course.