I was also drilled in the construction of every known kind of naval gun. Dozens of model war-crafts were shown to me and explained. I saw the model of every warship in the world. For days at a time I was made to sit before charts that hung from the walls of certain rooms in the Intelligence Department and study the silhouettes of every known varying type of war-craft. I was schooled in this until I could tell at a glance what type of a battleship, cruiser, or destroyer it was, whether it was peculiar to the English, French, Russian or United States Navy. As I shall show in relating one of my missions to England, I was brushed up on the silhouette study of British warships, for I had to be able to discern and classify them at long range. The different ranking officers of the navies of the world, their uniforms, the personnel of battleships, the systems of flag signals, and codes, were explained to me in detail. I was given large books in which were colored plates of the uniforms and signal flags of every navy in the world. I had to study these until at a glance I could tell the rank and station of the officers and men of the principal navies. The same with the signal flags. I pored over those books night after night into the early hours of the morning. My regular hours for tuition were from ten to twelve in the forenoon and from two until six in the afternoon. But it was impossible to compress all the work into that time. I was anxious to get my first mission, and I presume I did a great deal of cramming. My study was not all in Berlin. I spent most of my time there at Koenigergratzerstrasse 70 and at the Zeughaus, the great museum of the German General Staff. But there were side trips to the big government works at Kiel and Wilhelmshafen. There I was taught every detail of the mechanics of naval construction and I was not pronounced equipped until I could talk intelligently about every unassembled part of a gun, torpedo tube, or mine. In the course of my five months' instruction under the various experts of the Prussian Service I had many opportunities to observe the exhaustive thoroughness and the minuteness of detail which the German General Staff possesses. I did not lose the chance of this opportunity. I really did observe and see more than was intended for me to see. Of the amazing amount of labor, time and money that has been spent to gather the information contained in the secret archives of the German General Staff, the marvelous system of war that has been perfected in the German Empire, I shall tell when I consider the secrets of the War Machine. Naturally, I soon came to know still other things than what they taught me. I began to consider the whole proposition of Secret Service, and before relating my first important mission for Germany I shall tell you some of the general secrets of the System.