506 



any considerable changes in the present system of carriages, 

 and also to the employment of any contrivances, the working 

 of which would be dependent on the other carriages of the 

 train being provided with corresponding apparatus ; inasmuch 

 as the transmission of carriages from one line of railway to 

 another is so frequent, that on many of the great lines of 

 narrow guage rails we seldom find a train which is composed 

 of carriages all belonging to the same company, or of uniform 

 construction. 



Many engineers express a decided objection to allowing 

 passengers any means of communicating with the driver, 

 considering that more accidents and inconveniences might 

 arise from the abuse of such power than would be prevented 

 by its employment; but certainly there ought to be no 

 objection to permitting passengers to communicate with the 

 guard, who, after ascertaining the cause of alarm, might 

 communicate with the driver. 



Any means of communicating signals would be objection- 

 able if subject to uncertainty of action, and particularly 

 if any supposed signal might be accidentally given by the 

 motion or oscillation of the train itself. 



Signals given by whistles, or other means of producing 

 sounds, may be perfectly audible to persons on any carriage 

 following that on which such signal is given, but when the 

 train is travelling very rapidly, the loudest sounds from the last 

 carriage of a train are not easily heard by the engine driver. 



The giving signals on railway trains by means of electricity 

 is attended with many difficulties and sources of uncertainty. 

 The currents which can be made practically available are 

 slight, and are capable only of aifecting delicate apparatus. 

 If such currents are applied to produce the retention of a 

 keeper to an electro-magnet, so that the signal be given by 

 breaking the continuity of the circuit, the keeper is liable 

 both to be permanently attracted so as not to detach itself 



