242 



are materially reduced, so that eventually greatly increased 

 speed will be possible with complete safety. 



NORTH METROPOLITAN. 



A new electrical engine of the North Metropolitan Tramway 

 Company, Stratford, England, solves the problem of economical 

 working by combining electrical power with the aid of the me- 

 chanical application of the lever. The engine consumes only 

 two tons of coals per week, and will charge batteries sufficient 

 to do the work of four cars, requiring 44 horses per week. 



A curious fact connected with the development of the electro 

 motor occurred in Paris during the Exhibition in that city in 

 1873, when one of the workmen engaged in fixing the dynamo by a 

 mistake connected together the wires of the Gramme dynamos, 

 with the result that the electricity from one dynamo caused the 

 shaft of the other to revolve rapidly. This blunder gave to the 

 world the principle of the power of reversing the dynamo, and 

 formed the germ of the electrical railway. 



WORKING RAILWAYS BY AID OP ELECTRICITY. 



Without the aid of electricity the working of the railway 

 system of the present day with safety would be almost if not 

 quite impossible. 



BLOCK WORKING. 



By its means the block working of trains is carried on, and 

 it is now almost impossible to have what are known as " rear 

 collisions" on double lines where the system is in use. 



LOCKING SIGNALS BY ELECTRICITY. 



One system that came under my notice when travelling in 

 England was the application of electricity to lock the starting 

 signals from one station to another by making the train itself 

 perform the duties necessary for completing the signals, and 

 restoring the electrical current for setting a second signal. By 

 this means a signalman cannot lower his train- starting signal 

 to allow it to proceed to the next station until the signalman 

 at the station in advance has in reply to an arranged bell code 

 unlocked the signal lever. The electric lock having been taken 

 off enables the signalman to lower the signal, and on putting 

 it to danger again after the departure of the train to protect 

 it he cannot lower it again for a second train to follow on the 

 same I.ne until the lock is removed by the signalman at the 

 station in advance, and he is unable to take off this lock until 

 the first train has passed a certain point fixed by the railway 

 authorities. When the train passes this point the apparatus in 

 the signalman's box in the rear is re-set by the action of the 

 train itself, the weight of which deflects the rail and makes 

 •contact whereby the apparatus is re-set for the next following 



