A patent for a locomotive machine, bearing great similarity to Sir James Anderson's, last described, was taken out by Mr. A. Cochrane, on the 10th of the same month ; in conformity with which, a carriage was constructed and impelled through the streets of London soon afterwards; but from some defects in its construction, as well as from there being too few hands to work it, to overcome the weight and friction of the machinery, it did not perform satis factorily.
About this period several patents were taken out for improvements in the construction of the wheels for railway carriages. Mr. George Stevenson's plat congaed in combining wrought iron and cast iron, in the following manner The spokes are to be made of wrought-iron tubes, compressed from the circular into an elliptical form; these are to be laid and properly adjusted in the mould, in a true radialposition to receive the nave and the felloes, of cast iron, made by pouring the fluid metal round them. To obtain a perfect junction between the two different kinds of iron, the ends of the tubular spokes are previously glazed by the application of borax over the surface, and then heating the metal until the salt fuses over it. The ring which constitutes the felloes is cast in three portions, with an open space between them, which is done to permit the contraction in cooling, and to allow of their being afterwards keyed up firmly in their places.
Mr. Geo. Forrester, the eminent engineer of Liverpool, also had a patent in September 1831, in which he proposed to unite cast with wrought iron, by a very ingenious and beautiful process, especially with the view of constructing the wheels of railway carriages. The specification informs us, that there is first to be made a skeleton, or light frame of wrought iron or steel, of the form required, but of considerably less thickness. This skeleton is to be brightened by grinding, scouring or filing, so as to adapt it to be tinned. The article to be cast having been moulded in sand or loom, in the common way, the tinned skeleton is carefully laid in the middle of the respective parts of the mould, projecting pieces being attached to the former, to keep it in its proper place : the mould is now to be closed, and the cavities formed by the pattern are to be filled up with fluid cast iron, which completes the operation.
The locomotive steam carriage, contrived by Dr. W. H. Church, of Bir mingham, now comes under our observation. His first patent for locomotion is dated the 9th Febntary, 1832 • in this the principal novelties claimed are as follows :—First, the frame-work, which is not to be mortised together in the usual way, but united together by L, T, flat, and other shaped iron plates or bare, bolted on each side of the wood work, to obtain strength. This frame
work, well trussed and braced, encloses a space between a hind and fore body of the carriage, and of the same height as the latter, and is to contain the engine, boiler, &c. The boiler consists of a series of vertical tubes, placed side by side, into each of which is introduced a pipe that passes through, and is secured at the bottom of the boiler tube ; the interior pipe constitutes the flue ; each of diem first passes up through a boiler tube, and is then bent syphon-wise, and passed down another till it reaches as low, or lower, than the bottom of the fire-place, whence it passes off into a general flue in communication with an exhausting apparatus. Some other complications of tubes form a part of the arrangement, which our limits forbid us to descae. Two fans are employed. one to blow in air, and the other to draw it out; they are worked as usual, by straps from the crank shaft. The wheels of the carriage are constructed with the view of rendering them to a certain degree elastic, in two different ways : first, the felloes are made of several successive layers of broad wooden hoops, and these are covered with a thin iron tire, having lateral straps to bind the hoops together ; second, these binding-straps are connected by lunge joints, to a kind of at steel springs, somewhat curved, which form the spokes of the wheels. These spring spokes are intended to obviate the necessity, in a great measure, of the ordinary springs, and the elasticity of the periphery is designed that the yielding of the circle shall prevent the wheel from turning without propelling ! Dr. Church, however, proposes, in addition to spring felloee, spring spokes, and the ordinary springs, to employ air springs, and for that purpose provides two or more cylinders, made fast to the body of the carriage, in a vertical position, closed at top, and furnished with a piston, with packing'simihtr to the cap-leather packing of the hydraulic press : this piston is kept covered with oil, to preserve it in good order, and a piston-rod connects it with the supporting frame of the carriage. Motion is communicated by two steam cylinders made to oscillate, being suspended on the ends of the eduction and pipes over the crank ahaft. The crank shaft and driving-wheel axle are connected together by means of chains passing about pitched pulleys ; and there are two pairs of these pulleys, of different sizes withto each other, by which the power may be varied, by shifting the one pair to the other, by means of clutch boxes.