ELECTRIC cord of the kind furnished for connecting an electric flatiron with the supply, by way of a plug inserted in a lamp socket, is usually heavily insulated with a thick covering oif rubber and a sleeve of coarse woven cotton. For this reason it is rather difficult, when the conductor becomes broken inside its Covering, to locate the exact point of the break; because since the insulation is much stiffer than the stranded copper conductor itself, the ordinary bending test will not show the injury with any degree of certainty. Als an example, a household electric flatiron recently went dead,and an examination showed that the heating elements and the terminals of the iron were all right. To all outward ,ruppearances and tests the cord was all right, too; but a lamp connected by a pair of short wires to its apparatus end failed to light up. As it WaJS inexpedient to obtain a new cord at once, and the implement was needed immediately, the follOWing simiple test was resorted to: The plug on the end of tre cord bEing screwed into the supply socket, with the socket key turned to off, two common brass pins were inserted into the double cDrd, one into each conductor. The pins were so placed that tlJeir points pierced the cotton and rubber insulation and made contact with the stranded copper conductor within. The key switch was then turned on and an ol'dinary sixteen calidle-power incandescent lamp, held in the hand, was pressed against the heads of the two pins in such a manner that Dne pin made, contact with the metal sleeve of the lamp baBe, the other with! the, metal button in the center Df the base. The lamp immediately lighted up, showing that the cord was intact frOm the plug to the point where the pins were inserted. The current being turned off again, the pins were withdrawn, and replaced at a lower point in the cord that is, nearer the apparatus end-and the lamp was pressed against them. This process was repeated at intervals of a few inches until a SPDt was found, within a few inches of the flatiron end, where the lamp did not light up. The pins were then moved back and forth until the exact spot was found where the current ceased to flow. The cord was then cut off at this point and one o.f its conductDrs found to be broken cleanly in two.. I was an easy matter to strip the insulation from the newly-cut ends and refasten them in the flatiron connector plug, when the iron was found to be as good as ever. This is an extremely simple kink,but, like many other simple things, might not Occur to everyone who finds himself in the same predicament. The most important precaution to observe is to turn the current off before inserting or removing the pins. A shock in the fingers is not serious, but it is a trifle unpleasant, especially with alternating current at 110 volts. Soldering Flux.-A good soldering flux for copper is a heavy paste.of resin. This paste is made by dissolviiig as much resin in benzine as the benzine will take up. The paste is easily applied with a stiff brush.-H. D. Chapman.