Important: Safety Warning
This page describes trade processes that use dangerously toxic materials such as cyanide solutions, mercury amalgams, or strong acids. These processes require training, equipment, and precautions far beyond what the text describes.
This information has been left in for historical purposes but should not be acted upon.
Tempering Magnets
M. Ducoetet uses the following process for tempering and magnetizing steel to be used as magnets. Two soft iron pole pieces are placed in the bottom of a water tight vessel and are connected with the poles of a powerful electro-magnet. The vessel is partially filled with water, and oil is poured into the vessel, which floats upon the surface of the water. The red hot bar is then passed through the liquids and comes in contact with the magnets. This softens the steel without depriving it of its power of being magnetized.
To Engrave Name on Steel Tools. Coat the tool or article, if made of iron or steel, with a thin layer of wax, draw the name, initials or design through the wax, exposing the metal, and place the tool in a mixture of 6 parts by weight of water and 1 part of sulphuric acid. In a few hours remove, and if etched sufficiently, wash in clean water and dissolve the wax by heat. STOGDEN, MATTHEW. Inventor of the half-quarter repeating mechanism most used in English watches. He died in abject poverty, about 1770, at an advanced age.