REPORT OF MR. ROBERT B. LINES.
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collision, it will be seen that the "time ” system affords little or no safeguard.
The question has been very thoroughly gone into by Mr. Preece and by Colonel Tolland, Government Inspector of Railways in England. As long ago as 1862, the latter gentleman said :—
“ An interval of time, as a means of avoiding collisions between trains, is, in my judgment, worse than useless ; it is deceptive and thorough!} 7 uncertain, as an interval of half an hour at one station may have entirely disappeared before the train arrives at its next appointed stopping-place ; whereas, an interval of space, no matter how short, between following trains, if preserved, will always prevent a collision from taking place.”
At a very recent discussion of the subject before the Society of Telegraph Engineers in London, in which both these gentlemen participated, the conclusion arrived at was almost unanimous, that the "block” system, strictly carried out, was the only certain preventive of collision. If the block is absolute, and no other is safe or entitled to the name of block, there seems to be no alternative for the use of electricity in working and maintaining it. The employment of signal-men, within sight of each other, is not to be thought of, and yet it appears to be the only way to carry out the principle of the block without electrical aid.
The only approach to an equivalent of the block in America has, until lately, been found in the system of " train despatching,” but this requires, to be effective, a corps of skilled telegraphers, which cannot always be procured for railway service.
On some of the English railways, trains are run at intervals of three minutes under the block system. On the London and North-Western, the signal-stations are two miles apart, and on the Charing Cross extension of the South-Eastern Rail- way, less than a mile. While none of the American roads, probably, have anything like a corresponding traffic, there are many where trains run too frequently to permit of their being blocked at telegraphic stations irregularly located, and sometimes at long distances from each other. The train-de- spatcher’s order to a following train is, therefore, to " run as