From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Page from a document explaining the principles of magnetic force and magnetisation.
| Identifier | ExFiles\Box 35\1\ scan 172 | |
| Date | 11th August 1930 | |
| -2- Contd. In the absence of any positive knowledge of the real permeability of vacuo or non-magnetic material, we take it as being unity, so that the numerical value of the magnetic induction in such is the same as that of the magnetic force. Magnetic force is always due to one or both of two things :- (a) Electric Currents. (b) Free Magnetism (so called), mainly on the surface of, but partly in the material of, magnetic matter. Free magnetism to be explained in detail later. The actual or resultant magnetic force at any point in space, whether occupied by magnetic matter, non-magnetic matter, or no matter at all, is always the resultant of two components due to (a) and (b) above. MAGNETISATION. (2) When unmagnetised magnetic material is placed in the rigid + field of magnetic force, magnetisation is induced in the material. By magnetisation we mean a flux of magnetism in the material, which must be considered as properly belonging to the material itself and not to the space occupied by the material. There exists at the same time magnetic force in the space occupied by the material. This magnetic force, however, is not merely the original field of force which existed in the space before + See later. Contd. | ||