The ratio M/H is then found by one of the magnetometric methods which in their simplest forms are described below.
The magnetic condition assumed by a piece of ferromagnetic metal in different circumstances is determinable by various modes of experiment which may be classed as magnetometric, ballistic, and traction methods.
The magnetometric method, except when employed in connexion with ellipsoids, for which the demagnetizing factors are [[[Magnetic Measurements]] accurately known, is generally less satisfactory for the exact determination of induction or magnetization than the ballistic method.
The sample may have the form of a closed ring, upon which are wound the induction coil and another coil for taking the magnetizing current; or it may consist of a long straight rod or wire which can be slipped into a magnetizing coil such as is used in magnetometric experiments, the induction coil being wound upon the middle of the wire.
The magnetometric method was employed, and the metals, in the form of ovoids, were heated by a specially designed burner, fed with gas and air under pressure, which directed 90 fine jets of flame upon the asbestos covering the ovoid.