TRANSACTIONS OF SECTION G. 881 



under present conditions be kept running might be shut down. The author shows 

 this by diagrams representing the variation in the consumption of power in the 

 working of this railway, as given by Mr. Greathead. 



For several reasons the employment of geared locomotives is undesirable on 

 railways, although single-reduction gearing is most generally adopted for tram- 

 ways, and probably will remain best for that purpose. The noise made by high- 

 speed gearing and the wear are both objectionable, otherwise a geared locomotive 

 offers the means of overcoming, to some extent, the losses referred to. 



In the paper the author shows how an intermediate course can be adopted, 

 which will entirely remove the loss of power at the generating station. The 

 electric motor is placed directly on the driving-axle, but is reduced in size and 

 power to more nearly that of the mean horse-power required on the road. This, 

 for the greater part of the journey of a train from station to station, drives the axle 

 upon which it is placed, at its own speed, just as those do which are now upon the 

 South London Railway. The motor is. however, on a hollow spindle, which drives 

 the axle, when starting a train, through the medium of a compact double clutch 

 containing one pair of epicycloidal reducing wheels. The clutches are operated ty 

 electro-magnets or by fluid pressure. 



The train or locomotive may by this means be started at from one-fourth to 

 one-seventh of the speed of the motor. After a few seconds, the inertia of the 

 train having been overcome, the motor, the clutch-gear, and the driving-axle are 

 solidly coupled, and all move as one piece, the gearing only working during the 

 starting of the train. 



The motor may thus run idle upon the axle, or may drive the latter at one- 

 seventh of its speed, or at its own speed. A breakdown leaves the locomotive in 

 the condition of a gearless engine. 



For tramcars similar apparatus is described in the paper, which will drive the 

 car by a direct motor with starting ratio of gear of about six to one, or by single 

 reduction gearing will drive the car either at the usual gear ratio of about four t® 

 one, or, for starting, at a ratio of about twenty-four to one. 



4. On Self-exciting Armatures and Compensators for Loss of Pressura. 



By W. B. Sayeks. 



5. On a Mechanical System of Electrical Conductors. By E. Payne. 



These conductors have been designed with the object of providing a system of 

 mechanical conductors, constructed without the use of vegetable substances, which 

 shall not be open to the objection sometimes urged against the wood-casing and 

 covered wires usually employed for interior wiring, viz., that they are not composed 

 of fireproof and imperishable materials like gaspipes, waterpipes, and other fixtures 

 and fittings. 



The author began to work out the details of the system in the autumn of 1890, 

 in company with his partner, Mr. Carrington Smythe, and Mr. David Cook, wh© 

 is now the engineer and general manager of the City of London Electric Lighting 

 Company. 



The conductors consist of tubes, strips, rods, or wires of copper separated from 

 one another by insulators fixed at intervals, and usually made of glazed earthen- 

 ware. It was our object to construct the conductors so that they could be mad'3 

 up in lengths in the workshop and sent out ready for erection. 



The first experiments were made with tubes arranged on the concentric prin- 

 ciple, and consisted of a copper rod or a tube filled with bare wires placed inside 

 another tube ; when this was not used as an earthed return these were placed inside 

 a third tube which was used merely as a mechanical protection. 



The chief mechanical difliculties that had to be got over were (1) the fixing of 

 the insulators to the conductors, whether tubes, rods, or wires, so that they might be 

 sent out in lengths or in coils ready insulated ; and (2) the designing of suitable 

 junctions and junction-supports for the outside tubes. 



1893. 3 L 



