Fundamental Considerations Regarding the Use of Relative Magnitudes

In order to facilitate the use of relative magnitudes, the convenience of which for certain purposes has been demonstrated by the decibel, an examination is made of the fundamental relations applying to such quantities. Relative magnitudes are defined as quantities changes in which are expressed as ratios, which combine by multiplication, as distinguished from absolute magnitudes changes in which are expressed as differences, which combine by addition. It is shown that there are two number systems, conforming concurrently to the decimal system, by which relative magnitudes may be evaluated, and that the quantity 100.1 is the basic elementary number by which these two systems are related. The role of this number in computations with relative magnitudes is, in some respects, analogous to the role of the unit in computations with absolute magnitudes. It is suggested that the word "logit" is an appropriate designation for this quantity. Methods of employing this quantity, and the advantages of so doing, are discussed briefly.