Henry A. Chase, of Boston, Mass., has invented an improvement in cast-iron driving wheels for locomotives, which eonsists in casting the " counterbalance " in a double-plated chilled wheel opposite the crank-pin in the inner face of the tread, between the two sides, but not touching them. It is cast on the tread, and stands up from it in the hollow part of the wheel, like a plate, but is not attached to the hub. The plates of the wheel, therefore, are made of equal thickness throughout, and consequently when cast they contract equally. The counterbalance, or solid plate, cast opposite the crank pin, inside of the wheel, is therefore free to contract without iff ecting the side plates after being cast. Measures have been taken to secure a patent.