“Just what we have done, nevertheless. But you are right about steam. The _Mystery_ is not a steamship. We passed Sandy Hook Lightship at 10:31 last Thursday morning, and we reached the Needles at 4:38 this afternoon. Allowing for the difference in time, that makes our running time just four days, one hour, and seven minutes. The course we took was three thousand one hundred and ten miles, so our speed averaged about twenty-nine knots, or thirty-two miles an hour. We ran as high as thirty-five miles an hour for several hours in succession. If you doubt my statement and the evidence of the papers, I’ll be pleased to furnish you with additional proof if you will come on board with me,” and Captain Penniman watched the growing astonishment on the Englishman’s face with some amusement. “I cannot doubt your word, captain, but what you tell me is almost incredible,” spoke the collector after a long pause. He picked up the New York newspaper and examined the date-lines and dates of various news dispatches, as though still incredulous. “You know, captain, the speed record between the two ports is now six days, four hours, and some minutes. It was considered a great exploit when the new boats of the American Line cut the record down about seven hours recently. When you tell me you have reduced it by more than two days, you won’t blame me for being incredulous. You say the _Mystery_ is not a steamship. What in the name of modern wonders is she, then?” “We shall have to invent a new name for her, I reckon,” was the captain’s reply. “We use no steam, and carry no coal for her engines. She has no boilers in fact. Her motive power is liquified carbonic acid gas. We carry it in steel cylinders, and its expansive power, which is equivalent to a pressure of about two thousand pounds to the inch, drives our engines. Yes, she’s the wonder of the world to-day,” concluded the captain, proudly. “I never heard of such a thing. I thought you were going to say electricity. You Americans are doing everything by electricity now-a-days.” “No, electricity may come to it some day, but it costs too much, and it cannot be stored as this can. You will never get much higher speed with steam, because of the enormous consumption of coal required. We can carry enough liquified carbonic acid to drive the _Mystery_ three times around the world, and the cost is about twenty per cent that of coal. Come on board and look her over. We have kept her a profound secret on the other side, but now that we know what she can do, we are quite willing she shall have the fame she deserves. I guess the news of this trip will make a sensation in London, eh?” and the captain rubbed his hands softly and chuckled. “It won’t be believed,” replied the collector sententiously. “I will go aboard with you at once with the greatest pleasure. Let me finish entering you first. You have no cargo, I suppose?” “Yes, we have a small cargo.” “What is it?” picking up a pen.