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To Demagnetize Watches

As watches only become magnetized by being brought into too close contact with magnets, dynamos, and the like, it is an utter waste of time to try and demagnetize them by applying heat or cold, or rubbing on decoctions of various kinds. Magnetic influence is the only remedy for the evil. The application of the remedy is effected in various ways. If we suspect that a watch is magnetized, the first thing to do is to prove it. It is well to try all watches for magnetism before starting on repairs, and this can be done in the presence of the customer. Place a fair sized pocket compass on, or gummed to the under side of your show case glass, in such a position that when at rest the needle will point to O. Place the watch a little to the East or West of the compass and revolve it showly, watching the needle of the compass to see if the needle is deflected. Be careful to keep the centers of the watch and compass at a given distance apart. If magnetized, the needle of the compass will deflect to the right and left as the watch is revolved. Note the deflection at a given point, and then proceed to revolve. In this way you can closely approximate the location of the affected part. By taking the movement apart you can in the same manner readily determine the affected part or parts, and they can be demagnetized without much difficulty. All of the steel parts of a watch, except the balance and spring, can be readily demagnetized in the following manner: Place a bar magnet upon a piece of white paper, previously marked with lines, say one-eighth of an inch apart. Lift the affected part with a pair of brass or non-magnetic tweezers, and approach one end of it within one-eighth of an inch of the magnet, then reverse and approach the opposite end to within one-fourth of an inch; reverse and approach first end to within three-eighths of an inch, and so on until you reach a distance where the magnet exerts no influence. Test your piece, as previously described, with a compass, and if the cure is not effected, repeat the operation. The circular form of the balance renders it some what more difficult to treat successfully, and it is best demagnetized as follows: Fasten the balance on a large cork, say from one and a half to two inches in diameter, by means of a small brass pin bent at right angles, and amount the cork in your lathe and revolve. Take a ten-inch compound magnet and approach it as closely to the balance as possible, and then gradually withdraw the magnet, keeping the balance revolving meanwhile, thus presenting every portion of it to the influence of the magnetic force. In some cases it will be found impossible to demagnetize the balance, although the operation may be repeated many times. A close examination and test of the balance by means of compass will show that each arc of the balance has a positive and negative end, and the cross-bar will be found in the same condition. Under such circumstances it is absolutely unnecessary to thoroughly magnetize the balance by applying it to the magnet. You can demagnetize it, as previously described, without difficulty. It is advisable not to use your regular lathe in this operation, but rather to use some old lathe, or a polishing lathe will be found very desirable. See Demagnetizer.