56 ANNUAL OF SCIENTIFIC DISCOVERY. 



tion by aid of these results, and can only regret that some means were not 

 devised for ascertaining both these quantities, as well as the actual quantities 

 of water evaporated at short intervals. 



The performances of this engine, as above recorded are among the most 

 extraordinary recorded in the history of rail-road engineering. N. T. Tribune. 



IMPROVEMENTS IN RAIL-ROAD APPURTENANCES. 



Improved Air- Spring for Rail-road Cars. An improved air-spring has re- 

 cently been introduced on the Baltimore and Ohio Rail-road, of a novel con- 

 struction. The elastic material employed is common atmospheric air, and 

 the peculiarity of the invention consists entirely in the method of confining 

 it. The old air-springs employed to a considerable extent on some roads, 

 a few years since, consisted of a vertical cylinder, opened at the bottom 

 and furnished with a piston thrust up from below. It was abandoned in 

 consequence of its unavoidable leakage. The present spring consists of a 

 similar cylinder, or rather rough cup in an inverted position, provided with a 

 flexible but air-tight partition or diaphragm across its under side, and against 

 the under surface of this a suitable rounded mass of wood is allowed to press. 

 The air is compressed in the cup by the aid of a small hand-pump, and the 

 irregularities of the track cause the diaphragm to be bent alternately inward 

 and outward, so that the whole weight is supported on the cushion of air, yet 

 without allowing the least possible chance for the escape of the fluid. The 

 diaphragm is composed of several thicknesses of India-rubber, stout canvas 

 and leather, and as a still further protection is covered on the inside with a 

 stratum of good sugar-house molasses, so that the air, in fact, acts against a 

 fluid piston. The cast-iron cup is lined on its top and sides with tin to pre- 

 vent the possible escape of air through its pores, and the air, although com- 

 pressed to a density of some 150 pounds per square inch, is found in practice 

 to be completely and perfectly retained, while the motion of the car is, as may 

 be supposed, of the gentlest possible character. There is no friction, and the 

 only part of this spring which can fail is the diaphragm, which can be easily 

 and cheaply replaced when necessary. One of the most attractive qualities 

 belonging to this invention is its cheapness, a set for car, complete, costing 

 only about $40 or $45, while the steel springs frequently employed cost about 

 twice as much, and the now popular rubber springs cost from the like amount 

 to $150. 



Conical Plate Rail-road Car Springs. These improved springs, patented by 

 Speed & Bailey, of Detroit, Michigan, are simply concave steel plates, resemb- 

 ling, in outward appearance, the saucers of common coffee-cups. These disks 

 are placed within a case or cylinder, the lower disk resting, like a saucer, on 

 the bottom of the cylinder; the disk next above is reversed or placed bottom 

 up, its periphery resting on the periphery of the lower disk. In this manner 

 the disks are arranged in pairs, above each other, a plunger being fitted to 

 the top of the cylinder, on which the weight to be sustained rests. It is plain 

 that the elasticity of the disks, thus arranged, will be considerable, and that 

 they will yield more or less, according to the weight brought upon them. 



