Compressed air gramophones were

gramophone A phonograph, in its later forms also called a gramophone (as a trademark since 1887, as a generic name in the UK since 1910) or since the 1940s called a record player, or more recently a turntable, is a device for the mechanical and analogu ...

s which employed

compressed air Compressed air is air kept under a pressure that is greater than atmospheric pressure. Compressed air is an important medium for transfer of energy in industrial processes, and is used for power tools such as air hammers, drills, wrenches, and o ...

and a pneumatic amplifier to amplify the recorded sound. One of the earliest versions was the , designed by the Anglo-Irish engineer Sir Charles Parsons. It was capable of producing sufficient volume to broadcast public music performances from the top of the

Blackpool Tower Blackpool Tower is a tourist attraction in Blackpool, Lancashire, England, which was opened to the public on 14 May 1894. When it opened, Blackpool Tower was the List of tallest buildings in the British Empire and the Commonwealth, tallest man m ...

, and was said to be loud enough to cause people to vacate the front rows of seats in an auditorium.http://www.douglas-self.com/MUSEUM/COMMS/auxetophone/auxetoph.htm "The Auxetophone & Other Compressed-Air Gramophones" Retrieved 19 June 2012 The Auxetophone was sold in the United States as the Victor Auxetophone.

Pneumatic Amplifier

A was realised by using a sensitive valve, which required little force to operate, to modulate the flow of a stream of

. The basic principle of the valves used in these devices was to pass the stream of compressed air through two partially overlapping combs. The sound vibrations to be amplified were applied to one of the combs, causing it to move laterally in relation to the other comb, varying the degree of overlap and so altering the flow of compressed air in sympathy with the sound vibrations. The , designed for large halls, was a compressed air gramophone which employed

to amplify the recorded sound.Wierzbicki (2009), p. 74; "Representative Kinematograph Shows" (1907
The Auxetophone and Other Compressed-Air Gramophones
explains pneumatic amplification and includes several detailed photographs of Gaumont's Elgéphone, which was apparently a slightly later and more elaborate version of the Chronomégaphone. It was used by Gaumont for the presentation of some of their early

sound film A sound film is a motion picture with synchronized sound, or sound technologically coupled to image, as opposed to a silent film. The first known public exhibition of projected sound films took place in Paris in 1900, but decades passed before ...

s. Other compressed-air gramophones included the Elgéphone. (in German)

References

External links

Auxetophone and Compressed-air Gramophones
at Museum of RetroTechnology
What Happened to RokBlok? - The World’s Smallest, Wireless Record Player
Audio players Mechanical amplifiers Pneumatics {{sound-tech-stub