Wireless Developments.

Radio has long since ceased to be the scientific wonder it was in the pioneering days. To-day wireless is being pressed into commercial service in a hundred and one fields, and in the railway world interesting developments may shortly be anticipated in the use of radio. At Home, the railways are contemplating the introduction of wireless receiving sets on the principal main-line trains, while in the United States radio is being employed both for the entertainment of passengers, and for the purpose of inter-communication between moving trains and exterior points and between different parts of the same train.

Especially interesting is the effort of the Virginian railway in the wireless field. For operating over the mountainous sections of this line, it is usual to employ two locomotives for hauling freight trains, which sometimes run to as great a length as one mile. One locomotive draws the train in the ordinary way, while the second engine acts as a “pusher” in the rear. Wireless is being employed with marked success to ensure synchronous action between these two locomotives, particularly in starting and stopping. Special apparatus with loud-speakers is installed on the footplate of each engine, and by the employment of a code of signals similar to that used for steam whistles, the drivers are enabled to keep in constant touch and communicate with each other as may be desired.

Last month, it will be remembered, there appeared in the “London Letter” a simple little “passing trains” problem for the edification of our readers. Here is the solution, as promised: Fifteen trains would be passed, including the train which drew into A as you left, and the train which left B as you pulled in. Every hour there would be two trains in each station (one departing and the other arriving), and six on each line at hourly intervals, giving a total of sixteen trains. On each trip every train would pass all the other fifteen trains. Easy, isn't it!