Once in possession of secret information, the spy is faced with the necessity of transmitting it to Berlin. Here again, the spy who is a German would meet with considerable difficulty. He may mail letters if no mail censorship has been instituted; but these are liable to seizure and are not so useful in the transmission of war secrets as they were in informing his government before the war of more or less standard facts about the strength of fortifications and the like. He may use private messengers—as do all spies—but the delay in this method is a severe handicap. In sending news of the movements of troops, speed is the prime essential. Consequently he must communicate either by wireless or by cable. How does he do it? There are innumerable ways. There may be in the confidential employ of many business houses which do a large cable business with neutral countries men who are either agents or dupes of the German Government. These men may send cables which seem absolutely innocent business messages, but which if properly read impart facts of military value to the recipient in Holland, say, or in Spain or South America. It is not a difficult matter to use business codes, giving to the terms an entirely different meaning from the one assigned in the code-book. Personal messages are also used in this way, as is well known. As to the wireless, although all stations are under rigid supervision, what is to prevent the Germans from establishing a wireless station in the Kentucky Mountains, for instance, and for a time operating it successfully? But in spite of all cable censorship, the spy can smuggle information into Mexico, where it can be cabled or wirelessed on to Berlin, either directly or indirectly by way of one of the neutral countries. Even in spite of the most rigid censorship of mails and telegrams this sort of smuggling can be accomplished. When I was in the Constitutional Army in Mexico, I used to receive revolver ammunition from an old German who carried it over the border _in his wooden leg_. Could not this method be applied to dispatches? There are numerous authenticated cases of spies who have sent messages concealed in sausages or other articles of food. Moreover, the current of the Rio Grande at certain places runs in such a manner that a log or a bucket dropped in on the American side will drift to the Mexican shore and arrive at a point which can be determined with almost mathematical certainty. I mention those instances merely to show how little of real value the censorship of cables and mails can accomplish. The question arises: What can be done? I shall try to indicate the answer. HOW TO GET RID OF THE SPY SYSTEM.