But these two tricks of duty by no means end the marine's schooling. When he has become an efficient all-around man he may specialize. He may, if he chooses, go into the signal corps and learn the multitude of details connected with this ultramodern arm of the service. He learns to send messages by every possible means. He learns to operate a radio. And, it might be mentioned in passing, the Marine Corps is equipped with the very finest of radio apparatus. They have big trucks which carry the outfit and supply the power for either sending radio messages or operating huge electric searchlights. Or he may go into aviation.

INTERNATIONAL BOUNDARIES BEFORE THE WAR.
This map shows the boundary lines between nations as they were at the beginning of the war, as also the coast lines of Europe. The latter are brought out in bold relief.


CHAPTER XIV.

THE NATIONS AT WAR.

Unexpected Developments—How the War Flames Spread—A Score of Countries Involved—The Points of Contact—Picturesque and Rugged Bulgaria, Roumania, Servia, Greece, Italy and Historic Southeast Europe.

The real history of the greatest war of all times is the history of the entire world, touching every phase of existence in a manner that has never been approximated by any other conflict. The motives and ramifications are so great that it is almost impossible for the human mind to grasp the significance of many things of importance which, at a glance, seem to be but incidents.

The world looked on expectantly when the war started, because there was a general knowledge of the conditions existing in Europe and the undercurrent was felt by students of international affairs. But that Russia would revolt and the Czar abdicate, as he did in March, 1917, and the iron-ruled country would set up a government of its own—would join the circle of democracies—was not even hinted at. Neither was it intimated that Constantine I, King of Greece, would abdicate in favor of his son, Prince Alexander, as he did in the following June, under pressure, because of his sympathy for Germany.

Neither was there a suspicion that the fire started by the flash of a pistol and the bursting of a bomb in Bosnia would spread until sixteen countries were arrayed against Germany and Austria, supported by the Bulgarians and the Turks. And to these must be added the entrance into the conflict of Canada, Australia, New Zealand, possessions of Great Britain, and smaller possessions of other countries. The flames swept over the face of the earth in this fashion: