In an ordinary link motion engine (where both links are connected to the same weigh shaft), when linking up the high pressure cylinder to cut-off short, the same change is necessarily made in the low. By the use of the Joy gear, cut-off valves may be fitted to both cylinders, that for the low pressure being fixed at the constant position required by the proportion of the cylinders, while that on the high is adjustable; of course, in this case, the position of the quadrants must be only changed for reversing. In arranging the independent cut-off on the Joy gear, it is only necessary to increase the length of the vibrating link beyond the point of attachment for the main valve spindle connection to obtain a point from which motion may be taken to actuate the cut-off valve; even then the cost of the Joy gear for both cylinders is but little more than for a single set of link gear. This arrangement gives an absolutely perfect distribution of steam for compounding, also equalizes the power developed by both cylinders, and is far more simple and inexpensive than any other gear in existence. * * * * * THE STEAM BELL. [Illustration: FIG. 1.] [Illustration: FIG. 2.] The secondary railways in rural districts in Austria having no gates or bars at the level crossings, or guards at such points, but being open like tramways, special precautions are required to avoid accidents, and the public has to be warned of the approach of the train from a sufficient distance. This is done by ringing bells preferably to sounding whistles, as these are more likely to startle horses. The steam bell shown by our illustrations has been adopted for this purpose on the Austrian lines, and is a simple contrivance. It consists of a cylindrical chamber, a, ending in a narrower tube, c, which forms the seating for a flap valve, d, to which the hammer or clapper, e, is fixed. Steam is admitted through a small pipe, b, at the bottom, and after a certain interval attains sufficient pressure to lift the valve. The opening being large compared with the pipe, b, steam escapes more rapidly than it arrives through the small orifice; the pressure falls, and the valve drops down and causes the hammer to strike a bell surrounding the cylinder. The valve is provided with an internal collar as shown, so that it has to rise for the width of this before the steam is let out, and thus determines the swing of the clapper and the force of the blow. To intensify the latter and multiply the number of blows, the clapper spring is prolonged over the fulcrum and bent back so as to form a spring, which is tightened by the lifting of the flap, and sends the clapper down on the bell with increased force. The hinge of the flap does not require any lubrication besides what it gets through the steam. The bell is fixed upon the roof of the driver's cab, so that the steam does not interfere with his lookout, and fastened by three bolts or screws.