The Optical Magic Lantern Journal (August 1894)

132 The Optical Magic Lantern Journal and Photographic Enlarger. following stands without a parallel. Messrs. E. G. Wood, of Cheapside, have had for nearly fifty years in their employ a family of clever slide artists, extending to three generations, and as the grandson of the first artist has a young son who has also marked talents in this direction, it would seem that there is every chance of the succession being assured. * Ty our last issue, when commenting on the excellent management of the lantern at the Royal Institution on the occasion of Dr. Dallinger’s lectures, we omitted ‘to couple the name of Mr. J. W. Garbutt, of Upper Armley, Leeds. Mr. Garbutt has for a long time had the entire management of the lantern for Dr. Dallinger, and the excellence of his management has often been commented upon. * * 3 Tre late P. T. Barnum used to have the “‘preatest show on earth’' in connection with the circus. Is Mr. Walter Tyler, of Waterloo Road, 8.E., trying to follow suit in the lantern stock line ? Withiu the last twelve months he has bought up the stock-in-trade of three large dealers, the last being that of Messrs. Thomas & Co., of Acton, which was lately advertised in The Optical Magic Lantern Journal. AN optical and photographic exhibition is to be held at the Westminster Aquarium, from September 11th to October 6th. On July 2nd we were the recipicnts of a handsome present from Mr. F. Brown, the maker, given, it was said, in recognition of the way we had defended the use of saturators in general. When the numerous folds of tissue paper had been undone, we found a Gridiron saturator of superb finish, the body of which was ! silver plated and polished bright, the tubes and fittings silver plated and frosted, with name and taps lettered and shaded in blue enamel. Mr. Winter, the London Manager of Mawson & Swan, when admiring the apparatus, took its measurement, and said ‘‘ you must let us send you a glass shade and stand for this’ —and in due course they arrived. The saturator at present stands ready charged for use, upon blue velvet, and so perfect is the finish that it would almost seem a pity to handle it without gloves. We take this opportunity of thanking Mr. F. Brown, Mr. Winter and Messrs. Mawson and Swan for their kindness, and should any of our readers wish to inspect the gift, we will be pleased to show it any time by appointment. For many years past the old-established firm of J. Bernard & Sons, the well-known artists’ colour business, has been conducted by Mr. T. Claude Fairhead on behalf of the executors. This gentleman, in conjunction with Mr. F. Capel Cure, has purchased the business and plant, and will in future carry it on under the same name. With the same old name and two such energetic partners as the. gentlemen mentioned at the helm, a great increase of business may be looked for. ——:0:—— Lantern Slide Illustrating Sound Waves." 10! By Geo. M. Hopxrns. 703 In demonstrating the theory of sound, it is usual to illustrate the condensations and rarefactions of air which produce sound waves. by light and dark bands, which give an idea of the condition of the air at any instant in which it is transmitting sonorous vibrations. But these bands do not represent the progression of the sound waves. For an illustration of this, reference is often made to the concentric undulations produced on the surface of a mill pond by a pebble dropped in the water. This depends for its value upon the student having noticed the mill pond phenomenon and upon his ability to realise that these spreading rings relate only Fig. 1. Illustrating concentric waves. * Scientific American.