was directed against a glass plate immediately in front of a slit, on which light was concentrated by means of a lens. The jet was so arranged that the light on its way to the slit had to pass through the nappe and as the thickness of this was constantly changing, the illumination of the slit was also varied. By means of a lens ... an image of this slit was thrown upon a rotating gelatine-bromide plate, on which accordingly a record of the voice vibrations was obtained."

Tainter's story, in his autobiography, of the establishment of the laboratory, shows its comparative simplicity:

I therefore wound up my business affairs in Cambridge, packed up all of my tools and machines, and ... went to Washington, and after much search, rented a vacant house on L Street, between 13th and 14th Streets, and fitted it up for our purpose.[5]... The Smithsonian Institution sent us over a mail sack of scientific books from the library of the Institution, to consult, and primed with all we could learn ... we went to work.[6]... We were like the explorers in an entirely unknown land, where one has to select the path that seems to be most likely to get you to your destination, with no knowledge of what is ahead.

In conducting our work we had first to design an experimental apparatus, then hunt about, often in Philadelphia and New York, for the materials with which to construct it, which were usually hard to find, and finally build the models we needed, ourselves.[7]

Figure 3.—Page from Notebook of Charles Sumner Tainter, describing an experiment in sound recording. The Tainter notebooks, preserved in the U. S. National Museum, describe experiments at the Volta Laboratory, in the 1880's. The Graphophone patents of 1886, were the result of this research. (Smithsonian photo 44312.)

The experimental machines built at the Volta Laboratory include both disc and cylinder types, and an interesting "tape" recorder. The records used with the machines and now in the collections of the U. S. National Museum, are believed to be the oldest reproducible records preserved anywhere in the world. While some are scratched and cracked, others are still in good condition.

By 1881 the Volta associates had succeeded in improving an Edison tinfoil machine to some extent. Wax was put in the grooves of the heavy iron cylinder, and no tinfoil was used. Rather than apply for a patent at that time, however, they deposited the machine in a sealed box at the Smithsonian, and specified that it was not to be opened without the consent of two of the three men. In 1937 Tainter (fig. 1) was the only one still living, so the box was opened with his permission.

For the occasion, the heirs of Alexander Graham Bell gathered in Washington, but Tainter was too old and too ill to come from San Diego.

The sound vibrations had been indented in the wax which had been applied to the Edison phonograph. The following is the text of the recording: "There are more things in heaven and earth, Horatio, than are dreamed of in your philosophy. I am a