The Optical Magic Lantern Journal (December 1898)

176 the apparatus with a wet blanket and two buckets of water. No inflammable material shall be within two yards’ distance from the enclosure. The audience and seats shall at no point be less than 8 feet distant from the lantern; the audience being prevented from approaching by a suitable rail or barrier. (4.) The body of the lantern shall be constructed of wood or other non-conducting material, and shall be coated inside with asbestos; it shall also have an inner lining of sheet iron, and an air space shall be left between the iron and asbestos lining. In the bottom of the lantern shall stand an iron tray, which shall be surrounded by a vertical edge at least 1 inch indepth. The lantern shall be provided with a metal shutter, which shall fall freely between the source of light and the condenser. This shutter shall be immediately dropped in the event of any accident to the apparatus or stoppage of the film, and shall only be raised when the film is in motion for the purpose of projection. {5.) Where possible the electric arc light shall be adopted as an illuminant, the usual rules for securing safety in an electric installation being observed. Ether and other inflammable liquids shall not be employed under any circumstances for producing light. If limelight be used in the lantern the general regulations for its safety, which are issued by the Council, shall be complied with, and any additional precautions which the Council may deem necessary for securing safety shall also be adopted. The use of acetylene gas is not permitted. (6.) The space in which the cinematograph stands shall, where possible, be illuminated by electric glow lamps; but a miner’s safety lamp may be substituted, if necessary. No naked gas or oil flames, or matches, shall be allowed in the space. The lighting of the hydrogen flame in the lantern shall be accomplished by means of an electric lighter. (7.) The films, when not actually passing through the lantern, shall be kept enclosedin metal cases. The film which is passing through the lantern shall be rewound, either automatically or by hand, upon another bobbin as fast as it emerges from the lantern front. (8.) Not less than two, nor more than three, operators sha)l be engaged within the lantern space, and no other persons shall be within the lantern enclosure during the exhibition. The whole duty of one of the operators shall consist in taking charge of the film after it has passed through the lantern. (9.) The licensee shall be held responsible for the employmeot of competent, experienced and trustworthy Operators, and shall be prepared at any time to supply to the Council satisfactory credentials in this respect. (10.) Smoking within the lantern space absolutely forbidden at all times. shall {11.) The Council reserves to itself the right of modifying any of the above regulations and of requiring the adoption of any further precautions, in addition to those specified above, as circumstances may require. C. J. STEWART, Clerk of the Council. be | The Optical Magic Lantern Journal and Photographic Enlarger. The Kaleidoscope. fe wet HE kaleidoscopic attachment for a m2 lantern, while capable of giving \\ pretty effects, is for some reason or j} other seldom met with, although it may be obtained from, or at least through, any dealer in _ lantern apparatus in a compact form and in mahogany case for less than a couple of Pounds. This instrument is by no meansa difficult one to make. Cut two strips of looking glass, say about 7 inches long and 2 or 3 inches wide at one end and an inch smaller at the other; these two pieces of glass can now be fixed say by means of pieces of cork in brass or cardboard tubing, but in fixing them it is necessary that the angle at which they are to be placed be considered. If the glasses be placed at an apgle of 45 degrees the object on the screen will appear as eight angular parts; if 60 degrees eight parts, and if 90 degrees four parts, but perhaps the best angle at which to place the glasses will be 45 degrees. For experimental purposes ordinary plain glass may be employed, provided the backsare given a coating of opaque varnish. This appliance must be erected in front of the condenser so that the converging rays of light must fall just inside of the narrow end of the kaleidoscope. A lens having a focus a little longer than the length of the appliance can be used, in this instance say 8 inches. A highclass form of kaleidoscope has a lens at either end of the tube, so that the mirrors are practically within the tubing of the lens itself. Some little trouble may at first be experienced in getting it properly adjusted with regard to the light, and after the kaleidoscope is fixed it may be necessary to adjust the illuminant to and from the condenser, and also up and down and sideways, until as even an illumination as yossible is obtained on the screen. It will also be necessary to exclude all extraneous light at the front of the lantern. If any object, or a slide formed of two sheets of glass mounted close together and containing bits of coloured glass, beads, etc., be held at the large end of the tube the image will be multiplied so as to form a circle on the screen and each little movement of the object or slide will give a never-ending variety of design. As the size of the disc is doubled by this appliance the lantern must be placed in such a position as to allow for this.