Item from the Philadelphia Record, reprinted in the Indianapolis News, Mar. 13, 1878, p. 2.

"I would rather be the inventor of that little apparatus than president," and the speaker pointed to [a] small cast-iron framework standing on a table in the private office of Henry Bentley, at third and Chestnut streets. The little apparatus alluded to was Edison's phonograph, which is a miracle in the world of invention.  It consisted simply of an iron cylinder, traversed by a continuous hair indentation, over which was smoothly placed a delicate and sensitive covering of tin foil.  A disc about the size of a watch, with a hole in its center about one-half inch in diameter, constitutes the frame work of the speaking apparatus.  Over this hole is delicately adjusted a diaphragm of photographic iron, from the back of which projects a small steel needle secured to a rubber spring.  This is so adjusted that the needle gently touches the tin foil covering of the cylinder.  The mouth is placed close to the aperture in the circular disc, and, while speaking, the cylinder is revolved.  The force of the voice on the diaphragm causes the needle to vibrate, and this causes slight indentations to be made in the tin foil covering the cylinder.  For instance:

At the private exhibition yesterday the operator, seizing the crank, slowly revolved the cylinder, and, placing his mouth to the speaking apparatus, recited the lines

"Mary had a little lamb," etc.,

supplemented by a demonic laugh, and "Oh! oh!  Whoop!  1878.  How is this?"

The tin foil showed a continuous line of very fine indentations.  The cylinder was turned back to the starting point, and a funnel was placed over the hole in the mouthpiece, and the cylinder was again put in motion. 

The result was simply marvelous.  In a distinct tone, with the peculiar enunciation of the person who had spoken the lines, came the words of

"Mary had a little lamb," etc.
"Oh!  Oh!  Whoop.  1878.  How is this?"

It was like the voice of a very young child, but it was very plain and distinct.   This repetition of the lines spoken was simply caused by the needle passing over the indentations on the tin foil made when the words were spoken, and caused the diaphragm to vibrate over again as when the sound was first thrown upon it.  No electricity or any power is necessary, the whole invention consisting only of iron, the foil and the vibrating diaphragm with its needle.

The use this machine can be put to is manifold.  A business man desires to leave instructions for his clerk, who is out.  He sits down to the phonograph and pours into its mouthpiece all he desires to say to his clerk and goes out; subordinate comes in an hour later, or the next day or year, and places the trumpet over the hole and starts the instrument, and every word that was uttered was repeated.

"That is a mighty good thing for newspaper men," said a member of the guild, who was present.  "Imagine I had one in my office, I come down early in the morning disgusted with a leader in the morning issue, and, fearing my wrath will ooze out before the guilty wretch who penned it appears, I will sit down to the phonograph and give him the benefit of my feelings in this wise: 'Why, in the name of Heaven, did you occupy two-thirds of a column with claptrap platitudes on the weather.  My dydrant froze day before yesterday, and my butter spoiled last night.  Give Probs blue blazes to-morrow.  This thing can not be put up with.  Something strong this time, or beware.' 'I can go home relieved," he continued, "knowing that he will get blowed up by a machine which can not change a word or alter the emphasis."

Mr. Edison has also discovered a new element, made from the smoke of coal oil, which he condenses and uses as a vibrator in the tube of his telephones.  This is wonderfully sensitive, and a mere whisper will be transmitted by ordinary telegraph wire a distance of 20 or 30 miles.  In fact, Mr. Bentley, at his office at Third and Chestnut streets, heard Mr. Edison breathing in Germantown.