Proceedings of the American Philosophical Society Held at Philadelphia for Promoting Useful Knowledge Volume 47

Proceedings of the American Philosophical Society Held at Philadelphia for Promoting Useful Knowledge Volume 47

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This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1908 edition. Excerpt: ... tone strengthened. At the break, the old tone, already faint, would suddenly cease. Consequently, before breaking, both the old and new tones might be recognized, forming a sort of trill, or combination tone. This association of simultaneous tones had the effect of maintaining the primary current strength more nearly uniform. With the shorter tube-lengths, which involved a greater jump of frequency at the breaks, these combination tones were rarely heard, and the old note would break suddenly into the new note without any suggestion of a trill. In some of the observations, the notes, aside from the abovementjoned trilling near to the breaking points, gave acoustical evidence of multiple tones. Occasionally, the principal tone was accompanied by an octave overtone. The octave might be either the first octave below, or the first octave above, the principal tone. Such overtones were comparatively faint. At other times, the superposed tone, instead of being harmonic to the principal tone, appeared to differ therefrom by only about one tone on the musical scale. This inharmonic superposed tone was also relatively faint with respect to the principal tone. Generally, however, no superposed tones could be discerned, and the note was clear and flute-like in quality. Irregularities in the fitting of the telescoping tube-sections, or in other acoustic connections, were found to be productive of superposed notes. I Effects Of Electrical Changes. Observation Series 5. Effect of Resistance in Primary or Secondary Circuit.--In this test a single tube of constant length (86.5 cm. or 34 in.) was used. It was of pasteboard, had an internal diameter of 5.1 cm. (2 in.) and weighed 113.5 gm. This length happens to be about midway between the more

Product details

  • Paperback | 226 pages
  • 189 x 246 x 12mm | 413g
  • English
  • Illustrations, black and white
  • 1236976428
  • 9781236976420