. A text book of physics, for the use of students of science and engineering . 750 SOUND CHAP. means of a diagram similar to Fig. 633, known as Cheshires small circle ABC (Fig. 694) is equally divided into 12 parts bypoints on the circumference. Perpendiculars are dropped fromthese points upon the diameter AC and the feet of these perpen-diculars are taken successively as the centres of circles of graduallyincreasing radius. A is the first centre, then the next point to A,and so on until C is reached, and the diameter then retraversed. FIG. 694.—Cheshires disc. until A is reached again.
. A text book of physics, for the use of students of science and engineering . 750 SOUND CHAP. means of a diagram similar to Fig. 633, known as Cheshires small circle ABC (Fig. 694) is equally divided into 12 parts bypoints on the circumference. Perpendiculars are dropped fromthese points upon the diameter AC and the feet of these perpen-diculars are taken successively as the centres of circles of graduallyincreasing radius. A is the first centre, then the next point to A,and so on until C is reached, and the diameter then retraversed. FIG. 694.—Cheshires disc. until A is reached again. On covering up all but a strip EF, whichrepresents the pipe, and rotating the circles about the centre of thecircle ABC, the lines will vibrate longitudinally, N, N, N being nodesand A, A antinodes. It will be seen that the lines move from bothsides towards a node for half a vibration, and away from it for theother half. End correction of pipe.—It is found that the length of a closedpipe is not exactly one-quarter of the wave-length corresponding tothe fundamental ; neither is the length of the open pipe exactly LIS END CORRECTION OF PIPE 751 o-eRj 0-6 *r \ half the wave-length. The reason is that the reflection does notoccur exactly in the plane of the open end. From the nature ofthe reflection at the open end of a pipe, it follows that the processof reflection is not entirely confined to one plane. The effectiveend of the pipe is, therefore, not at its actual end but a small distancebeyond it. It has been found by experiment th
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Keywords: ., bookcentury1900, bookdecade1910, bookpublishe, booksubjectphysics
