The old high-pressure engine of Richard Trevithick, which, thanks to Mr. Webb, has been rescued from a scrap heap in South Wales, and re-erected at the Crewe Works.  We give engravings of this engine, which have been prepared from photographs kindly furnished to us by Mr. Webb, and which will clearly show its design.

[Illustration:  TREVITHICK’S HIGH PRESSURE ENGINE AT CREWE.]

The boiler bears a name-plate with the words “No. 14, Hazeldine and Co., Bridgnorth,” and it is evidently one of the patterns which Trevithick was having made by Hazeldine and Co., about the year 1804.  The shell of the boiler is of cast iron, and the cylinder, which is vertical, is cast in one with it, the back end of the boiler and the barrel being in one piece as shown.  At the front end the barrel has a flange by means of which it is bolted to the front plate, the plate having attached to it the furnace and return flue, which are of wrought iron.  The front plate has also cast on it a manhole mouthpiece to which the manhole cover is bolted.  In the case of the engine at Crewe, the chimney, firehole door, and front of flue had to be renewed by Mr. Webb, these parts having been broken up before the engine came into his possession.

The piston rod is attached to a long cast-iron crosshead, from which two bent connecting rods extend downward, the one to a crank, and the other to a crank-pin inserted in the flywheel.  The connecting-rods now on this engine were supplied by Mr. Webb, the original ones—­which they have been made to resemble as closely as possible—­having been broken up.  In the Crewe engine as it now exists it is not quite clear how the power was taken off from the crankshaft, but from the particulars of similar engines recorded in the “Life of Richard Trevithick,” it appears that a small spur pinion was in some cases fixed on the crankshaft, and in others a spurwheel, with a crank-pin inserted in it, took the place of the crank at the end of the shaft opposite to that carrying the flywheel.  In the Crewe engine the flywheel, it will be noticed, is provided with a balanceweight.

The admission of the steam to and its release from the cylinder is effected by a four-way cock provided with a lever, which is actuated by a tappet rod attached to the crosshead, as seen on the back view of the engine.  To the crosshead is also coupled a lever having its fulcrum on a bracket attached to the boiler; this lever serving to work the feed pump.  Unfortunately the original pump of the Crewe engine was smashed, but Mr. Webb has fitted one up to show the arrangement.  A notable feature in the engine is that it is provided with a feed heater through which the water is forced by the pump on its way to the boiler.  The heater consists of a cast-iron pipe through which passes the exhaust pipe leading from the cylinder to the chimney, the water circulating through the annular space between the two pipes.

Altogether the Trevithick engine at Crewe is a relic of the very highest interest, and it is most fortunate that it has come into Mr. Webb’s hands and has thus been rescued from destruction.  No one, bearing in mind the date at which it was built, can examine this engine without having an increased respect for the talents of Richard Trevithick, a man to whom we owe so much and whose labors have as yet met with such scant recognition.—­Engineering.