The Optical Magic Lantern Journal (August 1898)

The Optical Magic Lantern Journal and Photographic Enlarger. the fall of the plate r, which is the height of one of the pictures to be photographed. At the moment preceding thet at which the cam a would commence to raise the plate F, a second cam Gc! fixed at an angle upon the shaft © would engage with the lower end of the plate Fr, the film B would be at rest, the duration of such rest being the moment at which the picture would be photographed upon the portion of the film B facing the aperture c and lens pb, but the exposure may be varied by altering the formation of the cam p. The cam a iscircular, having a cut away portion a’, and at the moment preceding the next downward travel of the plate r, the cut away portion G’ would be | beneath the lower end a and so cease to push it © outwardly, when G would be immediately brought back against the partition c by the | tension of the spring g', when the pins d' would again engage with the holes f in 3, and again carry this down as before described. aa SOG ad Acetylene Gas Exhibition. YERByYON qe T the present time an interesting exhibition of apparatus for the generation of acetylene gas is being us held at the Imperial Institute, Se London. In one gallery the Z| apparatus is shown and in a shed oy outside most of the apparatus on y exhibition can be seen A committee of inspection keep a record of the behaviour of each generator, which will be embodied in their report. This exhibition will continue open till the 15th of September. About two dozen firms are represented, some making a speciality of large apparatus and others of apparatus which is self contained in a cycle lamp. Very few seem to cater for the lanternist, they probably thinking that if the gas can be universally adopted for house use, the attaching of an extension tube between the gas bracket and lantern is a simple matter. We are enabled to give illustrations of some of the apparatus on exhibition. In addition to large generators the Acetylite Syndicate, of Birmingham, make one specially for lanternists. A sectional view is shown at Fig. I., a shows the water tank, B the gas | c reservoir for holding a supply of | holder, 121 in action, a ; gasalier being set apart in one of the galleries for — each generator, each gasalier being fitted with | seven burners and labelled with the name of the | particular generator supplying it with acetylene. | ; granulated calcium carbide, p valve for controlling the supply of carbide which is to fall into the water, F cover which is fastened by means of two cam handles, G a collar for ballasting, 1 air outlet, K copper plate, o gas pipe, s outer water jacket, T vertical rod controlling valve pb. The working instructions are to lift the gasholder and contained carbide chamber out of the outer tank; fill the carbide chamber c, and screw down firmly the patent cover F; fill the inner reservoir A with water to within 2 inches s| more than half its height ; } fill the outer reservoir or water jacket s three-quarter Fig. I. full; replace the bell into the reservoir of water and let it sink slowly, opening the little tap at the top of the bell to discharge the air it contains; close the air tap when the hell, having descended until the valve rod touches the check plate, rises, owing to the fall of the carbide which produces the acetylene gas ; close the air tap and adjust the india-rubber to the gas tap at the base of the apparatus and to the lead pipe which passes down the column; the apparatus is ready for work when the burner in | the lamp is lighted. Kay’s patent generator, Tig. Il., manufactured by.the Manchester Acetylene Gas and Carbide Company, is the style on a large scale