It is natural to look to the railways of the first rank for the latest advances in construction, appliances, and equipment, and it is generally there they are found. Great trunk lines, crowded with traffic of all kinds, have not only the opportunity and means, but all the strong inducements to try or adopt any arrangement which promises 351 greater facilities for dealing with the ever-increasing demands made on their carrying powers. Passenger and goods traffic are so dissimilar in their requirements that when both of them are steadily increasing it becomes difficult, if not impossible, to work the two classes over an ordinary double line. In some cases much assistance has been obtained by shortening the lengths of the working sections and introducing intermediate electric telegraph block stations between the ordinary stations. Long refuge-sidings have also been introduced at many of the signal-cabins or stations, into which goods trains can be shunted out of the way to allow fast passenger trains to pass through without stopping. Up to a certain extent this arrangement works fairly well, but where there is a very frequent service of fast and slow passenger trains, combined with a heavy and constant service of goods and mineral trains, the two lines of way are practically incapable of accommodating such a number of mixed trains without causing serious detentions. The goods trains must shunt out of the way some time before a passenger train is due, and this frequent shunting into sidings results in hours of delay in the transit of the goods and cattle traffic; and when one of such trains is allowed to proceed again on its way up to another station, dove-tailed as it may be between two fast passenger trains, there is always the tendency to run at a much higher rate of speed than is prudent for the class of rolling-stock of which the goods train is composed. To overcome this difficulty some railways have introduced additional UP and DOWN lines on the busiest part of their system, making four lines of way in all, two of these being reserved for the fast passenger and through trains, and the other two for slow trains, goods, and mineral trains. This arrangement of the four lines has afforded great relief to the traffic of all kinds, and has enabled the service to be worked with much greater facility and punctuality. The goods trains being restricted to their own separate lines, can proceed regularly in their order, at their uniform working speed, without having to resort to the spasmodic fast running too often expected from them when passing over some parts of an ordinary double line. Doubtless this four-line system, or rather the principle of laying down two additional lines of way, will go on extending, and will be accelerated in its accomplishment by the growing demand for still higher speed of our fast passenger trains, and still longer distances to be traversed without stopping. High-speed long-distance through 352