An improvement in the construction of cars for the purpose ot accomplishing the object above named, has been invented by Archibald C. Ketchttm, of New York City; it is designed to be used in the running gear of cars, and all other carriages used on railroads. This invention is intended to prevent the liability of cars to run off the track in turning curves, by making all the wheels of the track follow exactly in line of the curve. To effect this result, each side of the truck is made in two parts, these parts being long rectangular plates of the required thickness to support the weight of the car, and connected in such a way as to admit ot their sliding, longitudinally in relation to each other, the bearing of one of the two axles being in one of the said parts and that of the other axle in the other part of the said sides. The two parts of each of the two sides being held with a transverse sliding bar, which is connected with a lever having its fulcrum on the inner axle, the opposite end of the lever being attached to the end of the car. The transverse sliding bar is furnished with two slots in each end, which receive studs projecting from the top of the bars, upon the sides of the truck, and are cut at such an angle to each other that, when the bar is moved by the action of the lever,in turning a curve, they will cause the studs to move within the slots, and the sliding sides to move longitudinally so as to bring the axle in the position of radii to the said curve ; by means of the arrangement thus briefly described, a rail car will be no more likely to run from the track in turning a curve, than in moving in a direct line. The structure of this car is not complex, and is at least worthy of a trial. Measures have been taken to secure a patent.