Robert Routledge, in his article upon railways, remarks:—“It may easily
be seen on looking at a line of rails that they are not laid with the
ends quite touching each other, or, at least, they are not usually in
contact. The reason of this is that space must be allowed for the
expansion which takes place when a rise in the temperature occurs. The
neglect of this precaution has sometimes led to damage and accidents. A
certain railway was opened in June, and, after an excursion train had in
the morning passed over it, the midday heat so expanded the iron that the
rails became, in some places, elevated to two feet above the level, and
the sleepers were torn up; so that in order to admit the return of the
train, the rails had to be fully relaid in a kind of zigzag. In June,
1856, a train was thrown off the metals of the North-Eastern Railway, in
consequence of the rails rising up through expansion.”