276 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1912. 



De Valbreuze published in 1911 in the Bulletin de la Society d'En- 

 couragement an interesting study on the use of electricity on railroads. 

 The following are a few of his conclusions : The principal advantages 

 resulting from the use of electric traction rest in the suppression of 

 smoke, the increasing of the capacity of the terminal station due to 

 the simplification of the maneuvering of the trains, and the possi- 

 bility of the use of steep grades so that more than one story may be 

 utilized at the station, the rapidity of starting, the multiplication of 

 trains, and, finally, the possibility of communicating from an exterior 

 source of energy as great an amount of power as may be desired. 

 Along with these technical advantages there are several economic 

 ones which result in diminishing the expenses of operation. Electric 

 locomotives have a smaller dead-weight than those using steam. 

 The power house for electricity uses steam engines of the highest 

 efficiency and fuel unsuited for ordinary locomotives. The mainte- 

 nance and repair of electric locomotives requires less time, and there 

 consequently results a greater annual mileage for them. 



The choice of the electrical method is a very complex problem, 

 demanding in each case a careful study, since no general rules can be 

 formulated. The proximity to a fall of water frequently determines 

 the adoption of electricity. From a military point of Adew tliis 

 method of traction possesses great disadvantages; the necessary 

 connection between the electric train and the power house constitutes 

 in the case of mobilization or of war a very serious inconvenience. 



Formerly railroad companies used for the transportation of freight 

 only cars of from 5 to 7 tons capacity. After 1855 cars of 10 tons 

 came into use; in 1879 of 15 tons; and in 1895 of 20 tons. In order 

 to go farther it became necessary to increase the number of axles, for 

 the European tracks could not support more than 12 tons per axle. 

 Accordingly, cars of 40 or even 60 tons were made, supported by 

 two small trucks, each having two pairs of wheels. 



This increase of capacity has the advantage that the ratio of dead- 

 weight to that of the carried load is reduced. For instance, the tare 

 of a car having a carrying capacity of 40 tons need not exceed 15 

 tons, whereas formerly cars for loads of 5 to 7 tons had a tare of 5 tons. 

 In order to lighten the cars further it became necessary to give up 

 the use of wood and iron in their construction. The solution of the 

 difficulty was found in the use of sheet steel, which is easily adaptable 

 to the designs suggested. 



These great cars have another advantage in that they reduce, 

 other things being equal, the length of the trains. Such a reduction 

 may amount even to 45 per cent. This augments the amount of 

 traffic possible at the station where, for the same length of platform, 

 about twice as much freight may be handled. At the same time the 



