308 Mr POWER, ON THE PREVENTION OP THE 



will be attended with the greatest danger whenever they occur. In- 

 deed it is manifest, that if during the ascent of the fore wheel, any 

 accidental cause should give the engine at the same time a hitch in 

 a horizontal direction, the fore wheels must be thrown off the rail, 

 as in fact took place in the present instance, occasioning the over- 

 throw of the engine and the disastrous consequences which ensued. 



Whether the above be the true solution of the accident it is possible 

 that a variety of opinions may exist ; but I conceive, no one will doubt 

 the importance of the principles which have been developed in the 

 course of this investigation, and which give rise to the following practical 

 conclusions : — 



1. In the construction both of the engines and carriages care should 

 be taken that the centre of gravity of each engine or carriage be about as 

 low as the horizontal frame to which the buffers and links are attached. 



2. If conformity with the above rule be attended with practical 

 inconvenience, the same object might be attained by placing the buffers 

 at the proper height, by means of strong additional frame-work, connected 

 with and rising from the general horizontal frame. 



I am not sure that a single pair of opposing buffers placed mid-way 

 between the rails, would not be better than two pairs of buffers placed 

 one immediately over each rail, in order to avoid any tendency to rotatory 

 motion in a horizontal plane, which any inequality of action in the latter 

 might occasion. But there may be practical objections to this arrange- 

 ment with which I am unacquainted. 



3. A further means of diminishing the danger would be to shorten 

 as much as possible the connecting chains, in order to constrain the 

 engines and carriages to move with the same velocity, and to prevent 

 the accumulation of any finite difference of velocities between any two 

 engines or carriages throughout the train*. 



* I have lately observed on the Birmingham railway that the buffers of the contiguous 

 carriages are forced into immediate contact, and the connecting chains made as tight as pos- 

 sible by means of a screw-power. Why might not the same mode of connection be adopted 

 when a pilot engine is attached, instead of a loose chain, which appears to be the usual 

 practice? If injury to the machinery be feared, arising from the jarring vibrations which 

 would accompany this contact, these might be prevented by furnishing the buffers of the 

 engines with springs similar to those of the carriages. 



