No. 2. Mr. Timothy Hackworth, of Darlington, "The Sans Pareil; weight, 4 tons, 8 cwt., 2 qrs.

No. 3. Mr. Robert Stephenson, of Newcastle-uponTyne, "The Rocket;" weight, 4 tons, 3 cwt.

No. 4. Mr. Brandreth, of Liverpool, "The Cyclopede;" weight, 3 tons, worked by a horse.

No. 5. Mr. Burstall, of Edinburgh, "The Perseverance;" weight, 2 tons, 17 cwt.

On the 6th, the first engine which experimented was "The Rocket" of Mr. Stephenson, an external view of which is represented in the preceding cut.

Its construction has been thus described in a periodical journal :—“The furnace, A, is two feet wide, by three feet high; the boiler, B, is six feet long, and three feet in diameter. The furnace has an external casing, between which and the fire-place there is a space of three inches, filled with water, and communicating with the boiler. The heated air from the furnace is circulated through the boiler by means of twenty-five copper pipes, of three inches each in diameter, which have their termination in the tall chimney C. PG, are safety valves; H H, the steam eduction pipes; D, one of two steam cylinders, which are placed in an inclined position, and embrace, like two arms, the boiler between them. E, one of the connecting rods, which give motion to the wheels; a, the slide-valves; and o, one of two escape-pipes. M is part of the tender appropriated to the carriage of the fuel; N, the water

cask."

From this description of Mr. Stephenson's machine, it is evidently capable of affording considerable power. A load was attached to it, of twelve tons, fifteen hundred weight, which it drew at the rate of from ten to eleven miles in the hour, and when the weight was detached from it, it attained a speed of about eighteen miles in the hour. This experiment, it would appear, was only intended as a rehearsal, and not as a decisive trial of its powers, as it was afterwards proved capable of producing more than double that effect, as we shall hereafter describe, in its proper place.

The next engine that exhibited its locomotive power was "The Novelty," of Messrs. Braithwaite and Ericsson, which was much admired for its lightness and compactness; the form being also very different to that of all other locomotives previously used, and the beauty or superior finish of its workmanship, made it an object of great attraction. In the annexed cut, a side elevation of it is given.

The preceding engraving, fig. 1, exhibits an externa. elevation of the machine. F, is the carriage-frame; E, one end of a long horizontal cylinder, forming the principal part of the boiler, which extends to the large vertical vessel A, at the other end of the carriage, and contains forty-five gallons of water; L, a hopper, to supply the fuel, (which is carried in small baskets placed on the carriage,) whence it is conducted by a tube in the centre of the steam-chamber A, into the furnace S, beneath. At C, is a blowing machine, the air from which is conducted by a pipe under the carriage, and proceeding by the tube K, enters the ash-pit M, under the furnace; Q, is a pipe for the escape of the heated gases after the combustion, and forms the only chimney used; B, is the water-tank; at D N are two working cylinders, with their steam-pipes and valves; the cylinders are six inches in diameter, and have a twelve-inch stroke; O G are connecting rods, which impart the force of the engines to the running wheels; the arrangement of these parts will be better comprehended by the annexed diagram, fig. 2.

The axletrees are fixed to an iron rod A, and slings are introduced at C, to prevent, it is said, the side action between the rod and the carriage-frame B; and to prevent the effect of the springs from counteracting the action of the engine, the connecting rods at D are placed, as nearly as possible, in a horizontal position, and the motion is communicated to them by bell-cranks at E, on each side of the carriage, being connected by the slings F, to the piston rods. The pistons used are the patent metallic of Barton, (described at page 427,) and the running wheels, the patent suspension kind, of Theodore Jones and Co. (See Journal of Patent Inventions, vol. ii. page 65.)

Fig. 3, exhibits a section of the boiler introduced by Messrs. Braithwaite and Ericsson, into "The Novelty" steam-carriage, which we are induced to insert here, as it has been deemed, by some influential persons, to be the grand desideratum in this branch of practical mechanics; it is, therefore, desirable that its real merits should come under the consideration of the reader.