PILOTING SHIPS INTO PORT
And now for the peace-time application of all this. If the compass could be used to find those who tried to hide, why could it not also be used to find those who wished to be found?
Every now and then a ship runs upon the rocks because it has lost its bearings in the fog. But there will be no excuse for such accidents now. A number of radio-compass stations have been located around the entrance and approach to New York Harbor. Similar stations have been, or soon will be, established at other ports. As soon as a ship arrives within fifty or a hundred miles of port she is required to call for her bearings. The operator of the control station instructs the ship to send her call letters for thirty seconds, and at the same time notifies each compass station to get a bearing on the ship. This each does, reporting back to the control station. The bearings are plotted on a chart and inside of two minutes from the time the ship gives her call letters, her bearing is flashed to her by radio from the control station.
Courtesy of the "Scientific American"
Fig. 12. Approaches to New York Harbor showing location of three radio compass stations and how position of a ship sending signals from A may be determined
The chart on which the plotting is done is covered with a sheet of glass. Holes are pierced through the glass at the location of each compass station. See [Fig. 12.] On the chart, around each station, there is a dial marked off in the 360 degrees of the circle. A thread passes through the chart and the hole in the glass at each station. These threads are attached to weights under the chart. When a compass station reports a bearing, the thread of that station is pulled out and extended across the corresponding degree on the dial. The same is done as each station reports and where the threads cross, the ship must be located.
Not only can the direction-finder be used to pilot a ship into a harbor, but it will also serve to prevent collisions at sea, because a ship equipped with a radio compass can tell whether another ship is coming directly toward her.
And so as one of the happy outcomes of the dreadful war, we have an apparatus that will rob sea-fogs of their terrors to navigation.
[CHAPTER XI]
Warriors of the Paint-Brush
When the great European war broke out, it was very evident that the Entente Allies would have to exercise every resource to beat the foe which had been preparing for years to conquer the world. But who ever imagined that geologists would be called in to choose the best places for boring mines under the enemy: that meteorologists would be summoned to forecast the weather and determine the best time to launch an offensive; that psycologists would be employed to pick out the men with the best nerves to man the machine-guns and pilot the battle-planes? Certainly no one guessed that artists and the makers of stage scenery would play an important part in the conflict.
But the airplane filled the sky with eyes that at first made it impossible for an army to conceal its plans from the enemy. And then there were eyes that swam in the sea—cruel eyes that belonged to deadly submarine monsters, eyes that could see without being seen, eyes that could pop up out of the water at unexpected moments, eyes that directed deadly missiles at inoffensive merchantmen. They were cowardly eyes, too, which gave the ship no opportunity to strike back at the unseen enemy. A vessel's only safety lay in the chance that out in the broad reaches of the ocean it might pass beyond the range of those lurking eyes. It was a game of hide-and-seek in which the pursuer and not the pursued was hidden. Something had to be done to conceal the pursued as well, but in the open sea there was nothing to hide behind.