Engineers and Mechanics Encyclopedia 1839: Railways: George Stephenson
About this period (1831) several patents were taken out for improvements in the construction of the wheels for railway carriages. Mr. George Stevenson's plan consisted 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 radial position, 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.
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