Patent for a new and improved car wheel. This design "consists in the combination, with a railroad-car axle having wheel-bearings of equal diameter throughout their whole lengths, of wheels the peripheries of which are provided with central flanges dividing each into two treads, the said wheels adapted to be pressed on the said bearings aforesaid, and to be removed therefrom, reversed, and again pressed thereon whenever the wear of the first tread shall render the same necessary" (lines 12-21).