MAXWELL'S EQUATIONS i.e. in mathematical symbols :

w

n.

here <§;, JE denote the dielectric displacement or polarixiiticm and ic magnetic induction respectively, c a scalar constant, the velocity f light in vacuum, n a unit vector normal to w, the sense of the itegration round s, of which d& is a vectorial element, being doek-ise for a spectator looking along n (see Fig. i). Mere, as throughout

ie volume, (ffin), etc., generally (AB), in round parenlhuses, denote; le scalar product of a pair of vectors :

(AB)=/l#cos(A, B),

f, B being the sixes or absolute values of the vectors A, B,* Thu.s, ie surface element da- being considered as an ordinary scalar, liur

irface integral I ((En)do- stands for the total number of Faraday tubes

mit tubes) crossing cr, and the surface integral in n. luis a similar leaning with respect to the tubes of magnetic: induction.

*If it were only for purely vectorial algebra and annlyniH, we cwiltl write, eaviside, for the scalar product simply AB. Bui nincc- w nhall hiivc to recur in the quel to Hamilton's quaternionic calculus, we reserve AB for tlieyW/quntrrrtiuuir oduct, and write therefore (AB) for the scalar product, i.e. for the alar part of the Ilanliltonian product, and VAB for the vector product, thus

AB = S. AB-I-V. AB