48 ANNUAL OF SCIENTIFIC DISCOVERY. 



cently been constructed in England. The steam cylinders are placed mid- 

 way between two pairs of driving wheels, which are so disposed as to bear 

 nearly the whole weight of the engine. A third pair of wheels are added, as 

 leading or travelling wheels, to complete the six required for the safety of the 

 engine. The cylinders are fitted and worked the usual way, but, instead 

 of having the piston passing out at one end of the cylinder only, it is carried 

 through both ends of it, which are filled witli stuffing boxes. This plan 

 saves the piston from undue friction. The cylinders are fitted and furnished 

 with connecting rods at the ends of the pistons, one set of connecting rods 

 communicating with one of the cranks on the leading driving Avheel axj, 

 and others with the cranks of the rear driving wheel axle. By this arrange- 

 ment the cylinders and pistons act in opposite directions, and the tendency 

 to oscillation is avoided. 



Automatic Steam Whistle. This is the invention of Mr. James Harrison, 

 Jr., and is a mechanical attachment to the engine, worked from the forward 

 truck axle, upon the principle that the axle makes a certain number of re- 

 volutions in working over the same distance, without any regard to the 

 speed. The motion is carried up to and along the top of the boiler to a cast 

 iron hollow cylinder, eight or ten inches in diameter, which is placed verti- 

 cally upon the boiler at the point where the whistle is to be fixed. On this 

 cylinder a screw is cut, intended to be long enough for adaptation to the route 

 of the locomotive out and back. Between the threads of this screw a lever 

 slowly traverses, and at the points where the whistle is to be blown, pins are 

 placed, over which the lever rides and raises a corresponding one, acting 

 upon the valve of the whistle on the top of the cylinder. 



Improvement in Journal Boxes. We notice the following improvement in 

 journal box for railroad car axles. It consists in making an inner box or 

 cell, with projecting lips, which embrace the lower half of the journal, to fit 

 and slide in recesses in the sides of a brass or cap box, so that when the 

 journal is inserted, and the inner box or cell is forced up against the journal 

 by springs, the whole circumference of the journal shall be embraced, to 

 prevent the entrance of dirt and waste of oil. 



Improvement in the Manufacture of Car Wheels. An improved method of 

 manufacturing wheels and axles is now being largely carried on in England. 

 The wheel is composed of triangular sections, each triangle being formed of 

 a rolled iron bar, bent into the required shape by a most ingenious opera- 

 tion, the base of the triangle being slightly curved, so as to form a perimeter 

 of the wheel; the ends are either inserted in a wrought iron nave; and, by 

 the insertion of a piece of iron at the angle of each triangular section where 

 it joins the next section, these being welded to each section, the wheels 

 become one piece of wrought iron, to "which the tires are mechanically fixed. 

 Such a wrought iron wheel tends greatly to preserve the axle, as every con- 

 cussion of the tire against the rails, instead of being directly communicated 

 to the axle, is distributed over a series of vibrations in the wrought-iron 

 wheels, and thus reaches the axle with greatly-diminished force ; and by 

 making the axle considerably stronger than the ordinary strain upon it re- 

 quires, the danger of fracture is reduced to a minimum. 



