AN interesting addition to the phonograph or the gramophone has been designed and made by Mr. Bowron, of 57 Edgware Road. It is well known that the action of a gramophone depends on a spiral line cut in the record disc. When this line is examined with a magnifying glass, it is seen to consist of numerous small oscillatory curves; as the disc rotates the needle that follows these curves actuates a diaphragm, and thus the sounds are reproduced. In other words, the curve cut on the disc is a graph of the various sounds produced by the instrument. Several years ago Prof. Ewing studied the analysis of vowel sounds by examining the corresponding curves cut on a phonograph record. Mr. Bowron has undertaken the task o of reproducing on a large scale the curves to be found on a gramophone record: he has accomplished this by means of a small mirror, which is mounted so that it oscillates with the diaphragm of the instrument; a beam of light is reflected from this oscillating mirror and from another mirror which rotates uniformly, with the result that a luminous curve of about three feet amplitude can be thrown on a white screen, and so made visible to a large audience. The variations in this luminous curve can be watched while the corresponding sounds are heard; thus the nature of the oscillations produced in the course of a song or the peformance of an orchestra can be most instructively studied.