RAILWAYS, ELECTRIC. 



677 



case for the conduction of the current, as they 

 are very roughly laid, and have to be shifted 

 from time to time. The electric conductors 

 are therefore placed along the roof of the 

 mine. They consist of inverted T-iron rails, on 

 which con tact -carriages freely slide. These 

 are connected with the motor by flexible wires. 

 The engine, shown in Fig. 1, consists of a car- 

 riage eight feet long by two feet seven inches 

 wide, which weighs one and one third tons. 

 The electro-motor is placed on it lengthwise, 

 the connection between it and the wheels being 

 made through the medium of bevel-gearing. It 

 is reversible, and handles for making and break- 

 ing the current, and the brake levers, are placed 

 at each end, so that the driver always faces in 

 the direction in which the engine is moving. 

 The engine is capable of developing sufficient 

 power to enable it to draw a load of eight tons 

 at a rate of seven and a half miles an hour. 

 This road has been in operation since October, 

 1882, and has fully realized the anticipation of 

 the constructors and the owners of the mines. 

 At the Paris Exposition of 1881, Sir William 

 Siemens had in operation a road about 1,600 

 feet in length, and of the ordinary gauge, 4 

 feet 8 inches. In this case the electric con- 

 ductors were suspended overhead, and con- 

 sisted of tubes provided with longitudinal slits, 

 for the passage of flexible conductors, which 

 were connected with metallic bolts sliding in 

 the tubes. Fully 95,000 passengers were con- 

 veyed over this line in seven weeks. The 

 longest electric railway which has yet been 

 built is that constructed by the London firm 

 of Siemens Brothers, in the north of Ireland, 

 between Portrush and Bushmills, a distance of 

 six miles. The line is a single-track one of 

 three-foot gauge, and is laid at one side of the 

 country road, following its grades, which are 

 heavy, being in some parts as steep as 1 in 35, 

 and curves which are often sharp. The sys- 

 tem employed is the three-rail one, but the 

 conductor, instead of being between the rails, 

 is placed at the side of the road-bed, 22 inches 

 from the inner rail, -and 17 inches above the 

 ground. It consists of a T-iron rail weighing 

 19 pounds to the yard, and is carried upon 

 wooden posts boiled in pitch to render them 

 better insulators. The current is taken by the 

 car from the conductor by means of two steel 

 springs, one at each end, and, as the rail is of 

 iron, the wear is very slight. When the rail- 

 way crosses roads, the conductor is carried un- 

 derground. These gaps, when not too wide, 

 are readily bridged over by the car, as the for- 

 ward spring makes contact with the rail at the 

 farther side of the cross-road before the rear 

 spring leaves the rail. When the gap is too 

 wide to allow this, the circuit is broken by the 

 engineer, and the car is carried across it by^its 

 momentum. There are five points on the line 

 at which the up and down cars pass each other. 

 These are situated on inclines, and are arranged 

 so that the car ascending the hill is in contact 

 with the conductor, while the down car de- 



scends by gravity. The course of the current 

 from the conducting rail through the car to the 

 return rails is to a switch worked by .: 

 by which resistance-coils can be placed in or 

 out of circuit, then through the electro motor 

 to the wheels by which it reaches tin 

 The direction of motion of the electro-motor 

 is reversed by altering the position of the 

 brushes on the commutator. The motor is 

 placed in the center of the car, beneatli the 

 floor, and is connected with the axle of one 

 pair of wheels by gearing. The reversing and 

 brake levers are placed at each end <>f t he- 

 car, so that it can be operated from either 

 end. The rails of the permanent way are laid 

 in the usual manner, and connected together 

 by fish-plates, these being supplemented by 

 strips of copper to insure good electrical con- 

 tact. The lengths of the conducting rail are 

 also joined in this manner. The resistance of 

 the line, conductor, and return rails, is but '23 

 ohm per mile. The loss due to resistance does 

 not exceed 4 per cent, when four cars are run- 

 ning, each requiring four horse-power. The 

 insulation is from 500 to 1,000 ohms per mile, 

 and the loss from leakage is under 5 per cent, 

 when four cars are running. It is intended to 

 operate the generating dynamo by means of 

 water-power, but at present an ordinary port- 

 able agricultural engine of 25 horse-power is 

 used for this purpose. This is not particularly 

 economical, but tests made have shown that 

 even with it the road can be operated more 

 economically than with a steam tramway-en- 

 gine. The tests were for a travel of 312 miles, 

 each train having the s'ame passenger capacity. 

 They showed that the cost of operating the 

 road by means of the locomotive was some- 

 thing over 8 ($40), and that by electricity a 

 little less than 6 ($30), giving a 'saving by the 

 use of the latter of 25 per cent. 



Edison and Field Railway. Mr. E<f ison was one 

 of the first to turn his attention to the electric 

 railway. While still occupied in designing his 

 system of incandescent electric lighting, he put 

 in operation at Menlo Park an experimental 

 line. On this the current was conveyed to the 

 electro-motor through one rail, and returned 

 by the other. The electro-motor was mounted 

 upon a separate car, as in some of the Siemens 

 roads. The use of the two-rail system was 

 simply experimental, the design being in actual 

 construction to use three rails, the conductor 

 being placed between the two rails in a sunken 

 trough. This is covered over, so as to leave 

 only a narrow slit, through which the anii rar- 

 rying the contact can move freely. In the 

 early part of the year the interests of Mr. Edi- 

 son were combined with those of Mr. Stephen 

 D. Field, who has patented a number of feat- 

 ures pertaining to an electric railway system, 

 and the company controlling these combined 

 interests exhibited their system at the Chicago 

 Exhibition of Railway Appliances. 



The track was laid in the gallery of the main 

 exhibition building, and was of the form shown 



