Descriptive catalogue of hydrostatic, hydraulic, pneumatic, and acoustic instruments : constructed and sold by Watkins and Hill, 5 Charing Cross, London.

  • Watkins and Hill
Date:
[between 1837 and 1851]
Catalogue details

Licence: Public Domain Mark

Credit: Descriptive catalogue of hydrostatic, hydraulic, pneumatic, and acoustic instruments : constructed and sold by Watkins and Hill, 5 Charing Cross, London. Source: Wellcome Collection.

    17/22 page 15
    136. 131. Horizontal Bellows with double riser, wind chest and sound board, with a set of wood pipes and metal tongued pipes, £7 17s. 6d. 132. The Svrene, to show the production of a musical sound by a succession of regular impulses, £3 13s. 6d.t £4 4s. 133. Willis’s Tube for the production of vowel sounds, adapted for using with the bellows, £2 2s., £3 3s. 134. A set of Membranous Apparatus to illustrate the mode of production of voice in the larynx, 7s. 6d. 135. Two Membranes to illustrate the vibration of the chordae vocales, 2s. 6d. 136. Apparatus for showing the inferior limit of audibility; that is, if regular impulses occur with less than a certain degree of frequency, the ear ceases to receive the impression of a continuous tone. This consists of a spur-wheel, which can be made to rotate with considerable rapidity; the rays pass edgewise through a narrow slit, and striking the air in passing, produce a series of regular impulses, £9 9s., £13 13s.
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