Page:Popular Science Monthly Volume 11.djvu/192

180 Some similar system should be adopted by railways leading out of New York, whose standard clocks could be connected at a trifling expense with the main clock, and kept right to within less than thirty seconds, which is near enough for most purposes. It should not be forgotten that each clock so controlled has the same accuracy as if it were directly controlled by the standard astronomical clock of the Naval Observatory at Washington, since the time which is obtained at that institution is directly distributed throughout the system.

For railways this system is peculiarly advantageous. Most railways adopt the time of one city as the standard time, by which all trains are run, and to which the watches of all employés are adjusted.

Suppose this should not be New York time, but another, as Poughkeepsie time, for example. A simple device, lately proposed by an ingenious writer in the New York Tribune, enables the New York clock to be controlled to both times. This consists of a double minute-hand—that is, instead of making a single minute-hand, make it double, with two pointers, so that when one points to New York time, the other points to Poughkeepsie lime. The controlling stop, or pin, acts upon the New York minute-hand, but the other hand ia equally kept right.

Such a clock will serve to control in its turn all the clocks along the line of the railway by a daily signal, so that at every railway-station the station-master's clock indicates, say, Poughkeepsie time. If required for the benefit of the citizens of each place, a second minute hand can be added to each of these secondary clocks, so that the local time of each station can be indicated, while at the same time each railway-clock affords the means to each railway-employé of correcting his own watch. This system, so simple in theory, is equally simple in practice, and requires nothing but the care and fidelity of the agents to whom its execution is confided to make it eminently useful and beneficial. It should be remembered, however, that to carry out its provisions carelessly is to commit a positive crime, since so much depends upon its results. Similar systems of control are now provided in many places. The observatory at Washington controls several clocks in the various departments; and in London, Edinburgh, Paris, Vienna, Bern, and elsewhere, this work is successfully carried on.

The distribution of time-signals (either with or without controlled clocks) to railways, etc., is a most important matter, in which the United States is far behind England, for example, where about five hundred railway-stations receive a signal daily. This is partly due to the enormous extent of America in longitude, so that very different local times are used at different places of the same continuous railway line, and partly to the fact that the telegraphs are owned by the Government in England, thus rendering the execution of a general system of time-signals comparatively easy. In the opinion of many experienced and prominent railway-officials in the United States, it is quite