Magnetic Permeability

—The relative ease with which a body conducts lines of magnetic force; the ratio between the magnetizing force and the magnetic induction; the coefficient of magnetic induction. Permeability is the conductivity for magnetic lines of force. In other words, it is a measure of the ease with which magnetism pa es through any substance, The permeability of good soft wrought iron is sometimes 3000 times that of air, varying with the quality of the iron. The magnetic permeability decreases as the magnetization increases. When a piece of iron has been magnetized up to a certain intensity its substance shows a tendency to reach magnetic saturation. In good iron this is reached at about 125,000 lines of force to the square inch of area of cro section,