The following account of an experiment made on the evening of October 9 by Alexander Graham Bell and Thomas A. Watson is interesting, as being the record of the first conversation ever carried on by word of mouth over a telegraph wire. Telephones placed at either end of a telegraph line owned by the Walworth Manufacturing Company, extending from their office in Boston to their factory in Cambridgeport, a distance of about two miles. The company’s battery, consisting of nine Daniels cells, was removed from the circuit and another of ten carbon elements substituted. Articulate conversation then took place through the wire. The sounds, at first faint and indistinct, became suddenly quite loud and intelligible. Mr. Bell in Boston and Mr. Watson in Cambridge then took notes of what was said and heard and the comparison of the two records is most interesting, as showing the accuracy of the electrical transmission:— BOSTON RECORD. Mr. Bell—What do you think was the matter with the instruments? Mr. Watson—There was nothing the matter with CAMBRIDGEPORT RECORD. Mr. Bell—What do you think is the matter with the instruments? Mr. Watson—There is nothing the matter with them. “Talking” from Boston to Cambridge Progress was rapid, and on October 9, 1876, we were ready to take the baby outdoors for the first time. We got permission from the Walworth Manufacturing Company to use their private wire running from Boston to Cambridge, about two miles long. I went to Cambridge that evening with one of our best telephones, and waited until Bell signalled from the Boston office on the Morse sounder. Then I cut out the sounder and connected in the telephone and listened. Not a murmur came through! Could it be that, although the thing worked all right in the house, it wouldn’t work under practical line conditions? I knew that we were using the most complex and delicate electric current that had ever been employed for a practical purpose and that it was extremely “intense,” for Bell had talked through a circuit composed of 20 or 30 human beings joined hand to hand. Could it be, I thought, that these high tension vibrations leaking off at each insulator along the line, had vanished completely before they reached the Charles River? That fear passed through my mind as I worked over the instrument, adjusting it and tightening the wires in the binding posts, without improving matters in the least. Then the thought struck me that perhaps there was another Morse sounder in some other room. I traced the wires from the place they entered the building and sure enough I found a relay with a high resistance coil in the circuit. I cut it out with a piece of wire across the binding posts and rushed back to my telephone and listened. That was the trouble. Plainly as one could wish came Bell’s “ahoy,” “ahoy!”[1] I ahoyed back, and the first long distance telephone conversation began.