If a portion of an article be required to be left soft, as the end of a spring that is to be bent or riveted, the entire may be tempered, and the end to be soft may be safely drawn in the lead bath to the lowest point that steel can be annealed without disturbing in the least the temper of the part not plunged in the bath. Springs, or articles made of spring brass, may be treated in the same manner. One great advantage in using the lead bath is that there is no risk of breakage or shrinkage of the metal at the water line, as is often the case when tempered by the method of heating and chilling in cold water. As lead slowly oxidizes at a red heat, two methods may be used to prevent it. One is to cover the surface of the lead with a layer of fine charcoal or even wood ashes. Another and a better plan, when the work will admit of its use, is to float on the top of the lead a thin iron plate, fitting the vessel in which the lead is contained, but having a hole in the centre or on one side, as most convenient, and large enough to readily admit the articles to be tempered or softened. _Test for Good Steel._—Break the bar of steel and observe the grain, which in good steel should be fine and present a silvery look, with sometimes an exfoliated or leaf-like appearance. One of the best tests of steel is to make a cold chisel from the bar to be tested, and when carefully tempered (be careful not to overheat), try it upon a piece of wrought iron bar. The blows given will pretty correctly tell its tenacity and capability of holding temper. Remember the temper you gave it, and if it proves tough and serviceable, take this temper as a guide and temper other tools in like manner. Inferior steel is easily broken, and the fracture presents a dull, even appearance, which may very appropriately be termed a lifeless look. _Etching on Steel._—Make an etching solution by pulverizing together sulphate of copper, one ounce; alum, one-quarter ounce, and common salt, one-half teaspoonful. Add one gill strong vinegar and twenty drops nitric acid. Stir till thoroughly dissolved. Polish up the metal to be etched, and then cover its polished surface with a thin coating of bees-wax. This can be accomplished with neatness by simply heating the metal till the wax flows evenly over its surface. Now draw upon the wax, cutting cleanly through to the steel the figure you wish to etch; then cover the figure so prepared with the etching solution, and let stand for a short time, depending upon the depth of cut desired. Finally rinse off with clear water, and then remove the bees-wax. It will be found that the solution has cut into the surface of the steel wherever exposed, leaving untouched all parts covered by the wax. Very good etching can be done by applying, on the foregoing plan, nitric acid alone. Etching offers a good method of cutting a man’s name on his gun or pistol. It works on silver or brass the same. CHAPTER XII. ON WORKING IN SILVER, COPPER AND BRASS.