Berthold. Vicars. Wright. Litteratur. Voigt. 1119 Holmes. Fog Horns and Sirens. Engin. XXX. No. 776. p. 432. Reclamation. E. B. Elliott. On musical intervals. Bull. Phil. Soe. Washington II, 199f. Der Gebrauch der Logarithmen der Schwingungsverhältnisse wird empfohlen. W. B. Taylor. On acoustic refraction. Bull. Phil. Soc. Washington II, 57f. Historischer Vortrag über die Störungen der Ausbreitung des Schalles. J. Henry. On sound in relation to fog signals. Bull. Phil. Soc. Washington Vol. II. Appendix No. IX. s. d. B. p. 275. — — On sound in Connection with fog signals. Bull. Phil. Soc. Washington H, 757. s. d. Ber. p. 275. A. E. Dolbear, of Bethany. On the Convertibility of Sound into Electricity. Amer. Assoc. for Advancement of Science 1873. n. z. — An Attachment to the Whirling Table for Pro- jecting LlSSAJOUS Curves. Amer. Assoc. for the Advance- ment of Science 1873. n. z. W. J. Millar. On the Mechanical Transmission of Sound by Wires and on Simple Forms of Microphone Receivers. Telegraphie J. n. z. Müller. Untersuchungen über einseitig frei schwingende Membranen und deren Beziehung zum menschlichen Stimmorgane. Sehr. d. Ges. z. Bef. d. ges. Natur, zu Marburg XI. Abhandl. 1-6 u. Supplemeutheft 1-5. Cassel 1876—80. n. z. Rayleigh. On reflections of vibrations of the confines of two media between which the transition is gradual. Proe. of the London mathematical Soc. No. 156-160. London 1880. n. z. A new phonograph. Journal of the Telegraph New-York. XIII. No. 293. III, 11. W. Voigt. Theorie des leuchtenden Punktes. Crei.le J. LXXXIX, 288-321f.