We Americans had seven submarines based on Berehaven, Ireland, whose "billets" were located in the approaches to the Irish Sea. The most spectacular achievement of any one of our boats was a curious mix-up with a German submarine, the details of which have never been accurately ascertained, but the practical outcome of which was indisputably the sinking of the German boat. After a week's hard work on patrol, the _A L-2_ was running back to her base on the surface when the lookout sighted a periscope. The _A L-2_ at once changed her course, the torpedo was made ready to fire, when the quiet of the summer afternoon was rent by a terrific roar and explosion. It was quite apparent that something exceedingly distressing had happened to the German submarine; the American turned, and made a steep dive, in an attempt to ram the enemy, but failed. Listening with the hydrophone, the _A L-2_ could hear now the whirring of propellers, which indicated that the submarine was attempting to gain surface and having difficulty in doing so, and now and then the call letters of the German under-water signal set, which seemed to show that the vessel was in distress and was sending appeals for aid. According to the Admiralty records, a German submarine operating in that area never returned to port; so it seems clear enough that this German was lost. Commander R. C. Grady, who commanded the American submarine division, believes that the German spotted the American boat before it was itself seen, that it launched a torpedo, that this torpedo made an erratic course (a not infrequent trick of a torpedo) around our ship, returned and hit the vessel from which it started. There are others who think that there were two German submarines in the neighbourhood, that one fired at our boat, missed it, and that its torpedo sped on and struck its mate. Probably the real facts about the happening will never be explained.