...electromagnetic density of the medium is expressed by 4 TT p, where /* is the magnetic permeability. The velocity of propagation of a disturbance through an elastic medium is numerically equal to the quotient of the square root of its effective elasticity e, by the square root of its density d, or...

...Jp/Js, in the limit, represents the ratio of unit stress to unit strain, and hence, is equal to n, the modulus of elasticity. Substituting, in equation...rapidly that the changes are sensibly adiabatic; hence (x, in equation (16), will be replaced by the adiabatic elasticity, and we have from which Substituting...

...not given here since it is somewhat difficult to follow, that the speed at which a wave travels in an elastic medium is numerically equal to the square root of the quotient of the elasticity by the density, using the appropriate units. In a gas such as air the decrease...

...equal distance. Indeed, the value of A is independent of this density as firstly the velocity a is equal to the square root of the ratio of elasticity to density, and this ratio remains the same for all layers of the air mass, as the assumption has already been...