April 9, 1886.J 



SCIENCE. 



3J9 



The carefully made estimates of this road may 

 be of interest as showing the minimum of cost of 

 good work, upon the authority of engineers thor- 

 oughly conversant with their profession. 



ELEVATED RAILWAY IK BERLIN, ONE METRE GAUGE, 6J4 MILES 

 LONG, WITH SEPARATE MOTOR FOR EACH CAR. 



Railway structure and 10 stations $335,000 



10 carriages, seating 15 persons each 15,750 



Steam-engine, boilers and dynamos 9,750 



Buildings 5,925 



Land 22,500 



General labor 3,575 



$362,500 



Current expenses. 



Wages $10,950 



Fuel 5,550 



Oil and waste 250 



Lighting 400 $17,150 



Depreciation and repairs: — 



3% on $312.530 $9,375 



U% on $25,000 4,000 13,375 



Interest on capital ($377,500) © 5£ 18,875 



$49,400 



It was proposed to run two hundred trips each 

 day at a fare of two cents per mile, and would 

 have proved a paying investment had it obtained 

 the equivalent of six passengers for a whole trip 

 for each car. 



Failing in this, Messrs. Siemens & Halske ob- 

 tained a charter, for a surface electric railway 

 from the Berlin military academy to Lichterfelde, 

 a distance of a mile and a half, which was opened 

 in May, 1881. This road was constructed upon 

 the ground after the manner of ordinary roads, 

 save that a bowed fish-plate connected the rails 

 so as to permit contraction and expansion. Again, 

 only two rails were used, — one conveying the 

 current out from the dynamo, and the other 

 returning the current to the dynamo. Very 

 little resistance was found, owing to the large 

 cross-section of the rails used as conductors, and 

 consequently low potentials were found prac- 

 ticable. Very great success has attended the 

 running of this road, and it has been extended to 

 Tetlow and Potsdam, making, in all, some eight 

 miles of road in successful operation upon or- 

 dinary roadbed with wooden ties and steel rails. 

 Insulated wheel-tires are used to take off the 

 current. 



At Paris the law required flat tram-car rails, 

 not projecting above the street-level; and the 

 presence of dirt would have interfered with the 

 passage of the electric current from the rails 

 to the wheels : so overhead copper conductors, 

 and trolleys running along the conductors, and 

 connected to the car by flexible wires, were 

 used. In the mines at Zankerode, Prussia, Messrs. 

 Siemens used two overhead rails for conductors, 



as the condition of the track prevented its use. 

 A separate motor, weighing a ton and a half, 

 drew loads of eight tons at a rate of seven or 

 eight miles per hour. In other cases, Messrs. 

 Siemens & Halske have found it advisable to use 

 a third rail, or separate copper conductor connect- 

 ed with the positive pole of the generating-dyna- 

 mo, and have connected the negative pole with 

 one or both rails of the roadbed. The Portrush 

 and Bush mills electric railway, six miles long, 

 has used a third rail so placed as to be free from 

 dirt, and has been in successful operation for 

 several years. Besides the Portrush railway, 

 there are now in successful operation electric rail- 

 ways at Brighton and Blackpool. Dupuy, at 

 Lisieux, France, has arranged a locomotive for 

 use in the bleaching-fields of a bleaching-works. 

 The power is carried in Faure accumulators on 

 the locomotive. Recently we have the experi- 

 ments upon the Reckenzaun secondary battery 

 tram-car at the Antwerp exhibition, which proved 

 itself the superior, in many ways, of the steam 

 and compressed - air motors entered in compe- 

 tition with it. When we compare the indicated 

 power of the engine charging the secondary bat- 

 teries with the power developed in moving the 

 car, we find an efficiency of from thirty to forty 

 per cent in this case. It is impossible to doubt 

 the ultimate success of electric railways when 

 built with sufficient knowledge and engineer- 

 ing skill to assure their adaptation to the pur- 

 poses which they must subserve. The success- 

 ful outcome of the work of Siemens & Halske 

 prove this beyond a doubt. The possibility of 

 attaching a motor to each car enables us, with 

 very little loss of space, to have each car 

 independent of any separate locomotive, and to 

 utilize the adhesion of all the wheels, and load. 

 The counter electromotive force of a dynamo 

 used as a motor, being proportional to its speed, 

 renders it to a certain extent automatic ; so that, 

 being at rest, the current passing is the most 

 intense, the torsion is a maximum, and the car 

 starts with a great pull. If the car slows on an 

 up grade, the pull at once increases, and, if it 

 goes faster on a down grade, the counter electro- 

 motive force increases, the intensity of the cur- 

 rent diminishes, and the demand for power upon 

 the generating-dynamo and engine is reduced. 

 The application of power to each car avoids the 

 necessity of an extremely heavy locomotive, and 

 allows of a great diminution of the weight and 

 strength of bridges and viaducts. 



A large number of electric railways have been 

 projected in this country, and some tried with a 

 moderate degree of success, as at Toronto, New 

 Orleans, Baltimore, and other places. The ex- 



