Gluck thought no more about it at the time. He merely re-wired his vat and went on electroplating. But afterwards, in prison, he remembered the incident, and like a flash there came into his mind the full significance of it. He saw in it the silent, secret weapon with which to revenge himself on the world. His great discovery, which died with him, was control over the direction and scope of the electric discharge. At the time, this was the unsolved problem of wireless telegraphy—as it still is to-day—but Emil Gluck, in his prison cell, mastered it. And, when he was released, he applied it. It was fairly simple, given the directing power that was his, to introduce a spark into the powder-magazines of a fort, a battleship, or a revolver. And not alone could he thus explode powder at a distance, but he could ignite conflagrations. The great Boston fire was started by him—quite by accident, however, as he stated in his confession, adding that it was a pleasing accident and that he had never had any reason to regret it. It was Emil Gluck that caused the terrible German-American War, with the loss of 800,000 lives and the consumption of almost incalculable treasure. It will be remembered that in 1939, because of the Pickard incident, strained relations existed between the two countries. Germany, though aggrieved, was not anxious for war, and, as a peace token, sent the Crown Prince and seven battleships on a friendly visit to the United States. On the night of February 15, the seven warships lay at anchor in the Hudson opposite New York City. And on that night Emil Gluck, alone, with all his apparatus on board, was out in a launch. This launch, it was afterwards proved, was bought by him from the Ross Turner Company, while much of the apparatus he used that night had been purchased from the Columbia Electric Works. But this was not known at the time. All that was known was that the seven battleships blew up, one after another, at regular four-minute intervals. Ninety per cent. of the crews and officers, along with the Crown Prince, perished. Many years before, the American battleship _Maine_ had been blown up in the harbour of Havana, and war with Spain had immediately followed—though there has always existed a reasonable doubt as to whether the explosion was due to conspiracy or accident. But accident could not explain the blowing up of the seven battleships on the Hudson at four-minute intervals. Germany believed that it had been done by a submarine, and immediately declared war. It was six months after Gluck’s confession that she returned the Philippines and Hawaii to the United States.