“On the night of the tenth of last June the maid brought me the card of a man who was waiting down-stairs, and who said he wanted to see me on very important private business. I glanced at the name scrawled in red ink on the bit of card-board,‘Martin M. Bradley,’ and wondered vaguely who the man could be, as I did not remember ever having heard of him before. “I told the maid to show him up here to the den, and a few minutes later she ushered into this room the man who has been the cause of these gray hairs. “He was short and sallow, about thirty-five years of age, as I afterwards found out, though care and privations had marked him so harshly that he looked to be nearly fifty. He carried in his hand this black, leather-covered box which you see in my lap; and, after seating himself at my invitation, began: “‘You are no doubt surprised, Mr. Churchill, to have a visit from me, for you probably don’t remember ever having heard of me before; but I’ve come to you because I know you are in the patent office, and used to be a friend of mine back in the seventies, and because, too, I’ve got something so valuable here that I don’t dare to send it up to the office in the usual way.’ “He unstrapped, as he spoke, the box, which he had not let out of his hands since he entered, and took from it two black, galvanized rubber instruments, one of which you see here.” Churchill lifted from the case a thing which resembled more than anything else the receiver of a telephone, except that both ends were turned out like the one you put to the ear. He unscrewed this outer cap and handed both parts to me to examine. About two inches in from the bell-shaped end of the cylinder was a diaphragm of peculiar looking metal, which from appearance I judged to be an alloy of copper and zinc, with something else included. Immediately over this, and tightly stretched across at unequal distances apart, were some twenty fine German silver wires. “Bradley opened one of the instruments, as I have just done,” continued Churchill, “and proceeded to explain to me its construction. “‘These two instruments,’ said he, ‘which together I call the Martin Bradley Seismaphone, are to the telephone what telegraphy without wires is to the ordinary method of sending messages. Both light and sound, as you know, travel by waves which produce sensation; one by striking against the retina of the eye, the other by striking on the drum of the ear. “‘The light wave travels with a velocity of something over 185,000 miles a second, while the sound wave moves much slower. This difference, however, is overcome by the mechanical device in the tube-like section in the middle part of the instrument.