The factor of **proportionality** will be I-41r, so that ' The principal theoretical investigations are summarized in Mascart and Joubert's Electricity and Magnetism, i.

The **proportionality** of the secondary disturbance to sin 43 is common to the present law and to that given by Stokes, but here there is no dependence upon the angle 0 between the primary and secondary rays.

Formulae, not involving the conception of an angle as generated by rotation, belong to this stage; the additional geometrical idea involved being that of the **proportionality** of the sides of similar triangles.

This want of **proportionality** will have a periodicity, that of the impinging waves, and so will produce vibrations just as does the variation of pressure in the case last investigated.

Then from the **proportionality** and parallelism sides of a triangle, there results the following of the load and the two resistances applied to each piece of the structure to the three theorem (originally due to Rankine): If from the angles of the polygon of loads there be drawn lines (Ri, R2, &c.), each of which is parallel to the resistance (as Pi F2, &c.) exerted FIG.

The above theory, coupled with such facts as the variation of the composition of the constant boiling-point fraction with the pressure under which the mixture is distilled, the **proportionality** of the density of all mixtures to their composition, &c., shows this to be erroneous.

Or because of the **proportionality** of the sides of triangles to the sines of the opposite angles, sin TOB: sin TOA: sin AOB:: a: ~: y, (8 A~

It was by an experiment of this kind that Quintus Icilius (1853) verified the **proportionality** of the heat absorbed or generated to the first power of the current.