The subject of our illustration is a railroad car brake of an improved construction, combined with small wheels that are placed between the main wheels of the locomotive and cars, so that when a train is passing over a curve, the small wheels can be lowered on to the inside rail of a curve, and from their small diameter and being free from the outside wheel they will prevent the cars running off the track. These small auxiliary wheels can be lowered or raised by means of a jack-screw, and can be made to lift the main wheels off the rail, and let the car run on them entirely, so that a car may be stopped or its speed slackened on a curve with perfect safety. In our engravings, A represents the truck frame of a car; B B, B' B', the main wheels; C C the auxiliary wheels, which are arranged between the main wheels, being attached by their axles, D D', to the perpendicular portions, a a, of jack-screws, E E', and are made to rise and descend by means of cogged sectors, G, which are on the shafts of the jack-screw pinions, H, and are caused to perform circular vibrating movements by means of horizontal rack bars, I, which have horizontal teeth, b, to gear with the sector teeth and other teeth which gear with the pinions of the vertical windlass shafts, L I/. The auxiliary wheels, C C, are held in place, while elevated as ij* shown in Fig. 1 by means of curved suspend-.C ed blocks, d d, which are pivoted to the guide ji|j boxes of the jack-screws, and are compound in form, internally to the curve of the small wheels and externally to the curve of the large main wheels. These blocks also serve as guides and stays to the auxiliary wheels when the small wheels are down upon the rails. With this arrangement of auxiliary wheels, it is evident that, by turning one of the windlass shafts, L , the rack bar, i I , will cause the sector, G', to turn, and the jack-screw, E, will descend, and carry with it the small auxiliary wheel, c, which, by coming in contact with the rail of the inward curve will elevate the inner side of the truck frame and the main wheels, B B, above the rails, and thus cause the weight of the car to rest upon itself and upon the main wheels, B B. The car thus adjusted, and with the auxiliary small wheel, C, elevated, will be in a condition for running with safety round the curve, as the small auxiliary wheel, C, will, owing to its decreased diameter, allow the large main wheels to travel over at much greater length of space than they themselves travel over, as may be necessary to compensate for the difference between the length of rail forming the outer and inner curves. The brake which is adopted for each car consists of four curved shoes, M M M M, one arranged to press on the upper part of the periphery of each main wheel. These shoes are connected together by means of transverse trusses, which are united and supported by an inverted arch. The braces and arch rest upon a transverse arm that has one of its ends suspended on a spring, and its other end pivoted to a vertical standard which is held in place, and supported by transverse beams, p. Above the loose or suspended end of the arm a longitudinal turning rod is arranged. This rod extends from end to end of the truck, and has a vertical brake-up lever, S, at one end, and a projection or cam at its center. The cam is grooved so as to receive the loose end of the arm on its underside, and the lever has a pawl pivoted to it which takes into a ratchet segment, and holds the brakes applied to the wheel so as to exert any amount of friction desired. There are springs for throwing the brakes up off the wheels when the ratchet and pawl are thrown out of gear. With this arrangement of brake it is evident that an equal pressure will be exerted upon all the wheels at the same time, by simply turning the rod in one direction, owing to the cam projection acting upon and depressing the pivoted arm, which is attached to and supports the arch, and the trusses to which the brakes are applied. This arrangement of brake is peculiarly adapted for use in connection with the small auxiliary wheels, as its shoes do not interfere with said wheels or their up and down adjustment. It is also better, as may be well known, than those arrangements of brakes which press longitudinally, and upward against the wheels, as it does not strain the springs upon which the boxes rest. The inventor is J. C. Fr. Solomon, of Baltimore, Md., and it was patented by him March 30, 1858. We noticed this improvement on page 243 of the present volume of the SCIENTIFIC AMERICAN, and the inventor will be happy to furnish any further information upon being addressed as above.