28 Railway Accidents. (January, 
5. Telegraph and the Block System.—In two papers on 
‘‘ Railway Accidents,” by Mr. Brunlees and by Captain 
Galton, read at the Institution of Civil Engineers in 1862, 
it was deduced from statistical tables that the great majority 
of accidents were attributable to preventible causes, and 
that, of these, 27 per cent were due to the absence of the 
electric telegraph. The advantages of the telegraph in 
connection with the working of railways were dealt with in 
an able paper by Mr. W. H. Preece, which was read at the 
Institution of Civil Engineers so far back as January, 1863, 
and although all the views expressed by him on the subject 
at that time have not met everywhere with approval or adop- 
tion, the system generally has come to be recognised as 
absolutely necessary for the safe working of any line of 
railway, and it forms a most important element in the now 
universally adopted block system. 
The first attempt of a block system introduced on rail- 
ways was by maintaining a presumed time interval between 
trains; this plan, however, failed, because those intervals 
could not in practice be observed; and the permissive 
system for reducing the time intervals by the aid of the 
telegraph, and sending trains timed to travel, and capable 
of travelling, at various speeds, one after another, into the 
seCtions, with a caution to each, may also be considered to 
have failed, because it does not afford sufficient protection 
to the traffic. Under these time systems collisions have 
occurred from engine-drivers slackening their speed to avoid 
collision with trains in front of them, and being run into by 
trains behind them. The greater the variety of speed 
between the trains, the more does the weakness of such 
systems become apparent. 
The proposal to divide the line of railway into telegraphic 
sections, and thus to preserve space intervals between 
trains, was made by Mr. (now Sir William) Cooke, as far 
back as 1842, and was first practised, it is believed, on a 
portion of what is now the Great Eastern Railway, in 1844; 
and, subsequently, a train telegraph system was established 
on portions of the London and North Western Railway. 
This latter, however, was not a block system, or a space 
system, but a time system worked with the aid of telegraph 
instruments, and it is now known as the permissive system. 
As regards the block system, there are many descriptions of 
instruments for working it, and various rules and regulations 
applicable to it on different lines of railway. The main 
principle involved is simply by the division of a line into 
block sections, and allowing no engine or train to enter a 
