"Am I to understand," said I, "that you have found a way of navigating both the atmosphere and the ether?" "As you see," he replied, briefly. "What the model has done, you are able to do on a larger scale--in a practical manner?" "Assuredly. It is only a matter of size." "And you can maintain the motion?" "As long as you like." "Marvellous! And how is it done?" "Ah!" exclaimed the inventor, "that is my secret. I am afraid I must not answer that question at present." "Is the plan not patented?" "No. The fact is, I have not yet investigated the subject as fully as I would like. My mind is not quite clear as to the causes of the phenomena. I have discovered a new field of research, and great discoveries are still to be made in it. Were I to patent the machine, I should have to divulge what I know. Indeed, but for the sake of my daughter, I am not sure that I should ever patent it. Even as it stands, it will revolutionise not merely our modes of travel, but our industries. It has been to me a labour of love, not of money; and I would gladly make it a gift of love to my fellowmen." "It is the right spirit," said I; "and I have no doubt that a grateful world would reward you." "I wouldn't like to trust it," replied Mr. Carmichael, with a smile and shrug of the shoulders. "How many inventors has it doomed to pine in poverty and neglect, or die of a broken heart? How often has it stolen, aye stolen, the priceless fruits of their genius and labour? Speaking for myself, I don't complain; I haven't had much to do with it. My withdrawal from it has been voluntary. I was born in the south of Scotland, and educated for the medical profession; but I emigrated to America, and was engaged in one of Colonel Fremont's exploring expeditions to the Rocky Mountains. After that I was appointed to the chair of Physical Science in a college of Louisville, Kentucky, where my daughter was born. One day, when I was experimenting to find out something else, I fell by accident upon the track of my discovery, and ever since I have devoted my life to the investigation. It appeared to me of the very highest importance. As time went on, I grew more and more absorbed in it. Every hour that I had to give to my official and social duties seemed thrown away. A man cannot serve two masters, and as I also found it difficult to carry on my experiments in secrecy, I resigned my post. I had become a citizen of the United States, but my wife was a Welshwoman, and had relations in England. So we came to London. When she died, I settled in this isolated spot, where I could study in peace, enjoy the fresh air, and easily get the requisite books and apparatus. Here, with my daughter, I live a very secluded life. She is my sole companion, my housekeeper, my servant, and my assistant in the laboratory. She knows as much about my machine, and can work it as well as I do myself. Indeed, I don't know what I should have done without her.