Volta Laboratory Disc Recording of the Word "Barometer"

What it is

This is a recording of the test word "barometer" made at the Volta Laboratory, which Bell ran, on 17 November 1884. It was recorded using one of four techniques described in a U.S. patent: a stylus controlled by a diaphragm varied a slit of light that exposed a spiral trace onto a rotating glass photographic plate.

Why it matters

This is one of the few Volta Laboratory recordings that had already been heard before being formally recovered, thanks to an earlier playback effort. It is signed by Harry G. Rogers, who worked with Sumner Tainter on these sound experiments, showing how Bell's laboratory pursued sound recording technology alongside the telephone.

Look closer

• Why would scientists test a single word repeatedly rather than record speech or music?
• What does the complicated recording method tell you about the technology available at the time?
• Who besides Bell contributed to this experiment, and what does that tell you about laboratory work?