curious confirmation of my experiment at Coloma. He related that a few days previous a friend had been out with him to try if the switch would turn in his hand. It did readily; but after dinner he found, upon a second trial, that there was no movement. This mystery was soon explained by the discovery that our neophyte was standing in his India-rubber shoes. Another important test I made at the Naval Academy, at Annapolis, a few years ago. I went there to look at Sir David Thompson's Electrometer, to ascertain if it could give me a clue to something which might guide me in the invention of the instrument in question. I could discover nothing from it, or from the most delicate galvanometer. One of the professors, however, asked me to give them a test. I called for a piece of iron wire, walked a few feet, put my foot down and said "There is something immediately under here." The board was taken up and disclosed the gas-pipe. I asked if they were satisfied. "You are a man of quick perceptions and might have noticed the direction of the pipe," was the answer. "Are you willing to be blindfolded?" I consented and succeeded repeatedly in locating the pipe, and what is more, in indicating other points of attraction to the rod, where all said that my experiment had failed, but which proved as full a confirmation of my theory as the lead pipe. These points were those where the iron columns supporting the building touched the ceiling underneath. Upon one occasion, I visited Professor Henry, of the Smithsonian Institute, and presented the subject to him. The professor took notes in a book, and asked for a test. I gave him several by locating the gas and water pipes. We then sat down and the professor remarked: "This is all personal influence." Of course, the question is none the less important or curious on this account, and I was a little nettled at the summary disposal of the matter. I therefore replied: "Professor Henry, you scientific men are always behindhand in discoveries, because you will not investigate, and it is left to those not well versed in the laws of science to ferret out mysteries and lay them bare. I present you two things, Professor--first, I find, by insulating myself that there is no motion of the rod, which proves electricity; second, I show that the motion begins at a certain point--an angle of forty-five degrees from the concealed water or metal--and the rod turns down directly over it; thus physical science and mathematics disprove your theory." I will say that my remarks moved the professor, who then showed a very decided interest and asked me to come and spend the following morning with him. Unfortunately, my departure from the city deprived me of the proposed interview. I have had many other experiences, but the relation of them would demand more time than it is expedient to give to them at present. I would add that I have observed in my experiments that the smallest underground stream