The Optical Magic Lantern Journal (April 1892)

The Optioal Magio Lantern Journal and Photographio Enlargor. The upper part of the cupboard is dark oak, with unpolished mahogany panels, and a motto in beaten brass-work. The lower doors are simply part of the pitch-pine lining of the wall. The working of a lantern cannot, as things are, be made an altogether easy matter, but with some such arrangement as has been described the purely mechanical labour at least is reduced to almost nothing. At the same time the installation, instead of disfiguring the room, as might have been expected, is when closed up decidedly ornamental. 203 The Lanternist’s Den.— No. 2. By C. E. Renn.e. SOLDERING, SOLDERING is such an every-day accomplishment that an apology is needed for its introduction here. But I think a few hints on the subject may not altogether be out of place, more especially as the reader has now his own place in which to work, where he can often practise what he thinks he will, away from the eager gaze of the curious and critical. Some short time ago I noticed in a window, ‘The complete soldering outfit,” at the modest cost of sixpence. “ A cheap present,” thought I to myself, “for one of the boys.” SoI entered the establishment and asked to be shown the “complete outfit.” Disappointment, however, was my reward, as I was handed a card on which was tied a strip of pewter solder, a very small bottle of fluid, and a miniature-looking poker. There was just sufficient of these three to make one expostulate in his solitude as to his sanity in purchasing a toy, for the solder and fluid might, with a struggle, run round the lid of an ordinary saucepan, but the poor little iron would have had to undergo so many heating operations as to make the whole process useless. By the way, it may only have been intended for tacking together a child’s tin soldier, PEwTeR SOLDER. To be accurate, solder is employed for the purpose of cementing, binding, or uniting together, edge to edge, or surface to surface, by the aid of heat, metals of less fusibility. The metal may be—tin, brass, copper, silver, gold, or what you will, the rule applies to one and to all alike. The solders used in lantern construction are but three, those we call pewter, spelter, and silver. Each can be bought ready for use, but an analysis of their component parts and. means of preparation may be of interest. Pewter is commonly called soft solder, because of its use on substances so much harder than itself. The 45 melting point is extremely low compared with those which will hereafter be dealt with. It oftentimes proves a pest to the worker in precious metals, inasmuch as it adheres to gold or silver when burnt on, its eradication is most difficult, and the beauty of many a costly ornament has been marred by it, when falling into inexperienced hands. To make soft solder—Take of pure. grain tin two parts, say 202. ; of pure lcad, one part, say 10z. The melting temperature of lead is about 61odeg. Fahr.; of tin, 440deg. Fahr. Put the lead into a small iron ladle on a clear fire; meanwhile the grazuz tin may be getting hot on the hob, or other convenient place. When the lead has properly melted (and be careful that it does not burn), drop into it, by degrees, the hot tin, stirring the while with a piece of wood, which will greatly facilitate incorporation, and when thoroughly mixed, remove from the fire. With a piece of flat wood skim from the surface any dross that may have collected, allow it to cool down to below ignition point (that is to say, if a piece of paper refuse to ignite when stirred into the molten metal), pour slowly and steadily into strips upon a clean hearth. These strips, when cold, may be hammered flat to the’ required thickness for use. If poured very thick, the flattening process will make it hard, and it perhaps may break and crack, but this can be avoided by annealing. “ Anneal lead?” yousay. Certainly. Why not ? Rule flat to half thickness, place over a gas fame a piece of sheet iron on which lay your solder. As soon as hot enough for a drop of water to hiss from it, let cool slowly, when it will be found again quite soft and perfectly annealed. Flat again to half thickness, again anneal, if necessary, andsoon. We have now a sound and reliable solder, which can be best kept clean in a tin canister for use when required. Sort SOLDERING Fiurp. There are several agents which stimulate the flow of soft solder. Resin, tallow, venus turpentine, chloride of zinc, &c.; the last-named being the cleanest, most convenient, and easiest to work | we will adopt it. Take hydrochloric acid (spirits of salts), five parts ; metallic zinc, two parts. Cut into small pieces the metallic zinc(which must be clean) and put into a small earthenware pipkin, or similar vessel, over which pour your acid. The chemical action of the acid will at once be apparent, and the scrap becomes dissolved with an evolution of hydrogen gas. The fumes being offensive, it is advisable to place it on the hob, or outside the window. When all action has ceased, drop in one or two more pieces of zinc to ascertain whether any energy be left in the salts,