FILES

The manufactures of these articles do not come within the limits of this work. It may, however, be useful to mention that FILES , FLOATS , and RASPS , which “cut dull” from age, dirt, or being much worn, are greatly improved by being kept wet, immersed in water for some hours, or even for a day or two. Mr Ernest Spon recommends the following method for renovating files:—The file to be first cleansed from all foreign matter, and then dipped in a solution of one part of nitric acid, three parts of sulphuric acid, and seven parts of water; the time of immersion will be according to the extent the file has been worn, and the finene of the teeth, varying from five seconds to five minutes. On taking it out of the mixture, wash in water, then dip in milk of lime, wash off the lime, dry by a gentle heat, rub over equal parts of olive oil and turpentine, and finally brush over with powdered coke.