Sound / by John Tyndall.

  • Tyndall, John, 1820-1893.
Date:
1883
Catalogue details

Licence: Public Domain Mark

Credit: Sound / by John Tyndall. Source: Wellcome Collection.

Provider: This material has been provided by UCL Library Services. The original may be consulted at UCL (University College London)

    26/494 (page 4)
    tant, that I propose to illustrate the propagation of sound by another homely but useful experiment. I have here five young assistants, A, B, c, D, and E, fig. 2, placed in a row, one behind the other, each boy's hands resting against the back of the boy in front of him. E is now foremost, and A finishes the row behind. I suddenly push a, a pushes B, and regains his upright position; B pushes c; C pushes D ; d pushes E ; each boy, after the transmission of the push, becoming himself erect. E, having nobody in front, is thrown forward. Had he been standing on the edge of a precipice, he would have fallen over; had he; Pig. 2. stood in contact with a window, he would have broken the glass; had he been close to a drum-head, he would have shaken the drum. We could thus transmit a push through a row of a hundred boys, each particular boy, however, only swaying to and fro. Thus, also, we send sound through the air, and shake the drum of a distant ear, while each particular particle of the air concerned in the trans- mission of the pulse makes only a small oscillation. But we have not yet extracted from our row of boys all that they can teach us. When A is pushed he may yield languidly, and thus tardily deliver up the motion to his neighbour B. B may do the same to C, C to D, and D to E. In this way the motion might be transmitted with comparative slowness along the line.^ But A, when pushed,