C A ; in other words, it is impossible that the circumference of a circle multiplied by half its radius can be the measure of a greater circle. ... the circle whose diameter is unity be denoted by a- ; then, because circumferences are to each other as their radii or diameters, we shall have the ... to the number above designated by ir J and the simplicity of this first approximation has brought it into very general use.
|Title||:||Encyclopædia metropolitana; or, Universal dictionary of knowledge, ed. by E. Smedley, Hugh J. Rose and Henry J. Rose. [With] Plates|