My first desire in taking charge of the Squad was to suppress the activities of persons using explosives to destroy life and property. What knowledge of the physics and chemistry of explosives my experience had accumulated I passed on to the men. These periods of instruction went into considerable detail. We discussed the kinds of explosives used, their relative strength, their ingredients, the methods of detonating them, the containers into which they were loaded, and the use of clockwork, fuses, acids and gas-pressure to explode them. Special and explicit instruction was given for the handling of unexploded bombs--a bomb bearing an electrical attachment should not be placed in water, for example, as water is a conductor of electricity; it is wise never to smoke in the presence of explosives, even if you think you know that certain kinds of explosives “_never_ explode by fire.” The only thing you can depend on explosives to do one hundred times out of one hundred, is what you don’t expect them to do. The Bomb Squad was told never to--and why never to--carry bombs on passenger trains, cars or ferries, or anywhere near where metals were being shipped. The Bomb Squad was instructed not to remove a bomb found in a position where its explosion would not endanger life and property, but to send for an expert and wait until he arrived on the scene, and was told which positions were dangerous and which were not. Altogether we conducted a rather thorough course in explosives. As the war grew in proportions, and the interest of America in the conflict became more and more intimate, the activities of the Bomb Squad became somewhat diverted from the object for which it had been primarily organized, and its title was changed to the “Bomb and Neutrality Squad.” We had not expected in August that the German would try to tip over our neutrality with bombs, but that is what he did, and that is what kept us grimly busy for three years, until our own nation had gone to war with those who had so long been waging war upon her. And that is how the stories which follow come to be told. Not that the entrance of the United States into the war put a stop to the activities of the Squad. I have already cited those who entered the national service. Their presence in the Naval and Military Intelligence, their close relations with those whom they left behind in headquarters, with such men as Commander Spencer Eddy and Lieutenant Albert Fish of the Navy, Colonel Biddle and Major Potter of the Army, and with the Corps of Intelligence Police, made possible a degree of coöperation in spy-hunting in New York which would have been impossible to develop within a short time with any other set of men, and which went far towards preserving our domestic security. II WESTPHALIAN EFFICIENCY