On quantization of mass and electrical charge

Suggested a nonlinear modification of Maxwell's equations, based on geometrical idea. The potential of a charged particle at rest is calculated; the result is quantization of electrical charge with correct values, $-e, -e/3, 2e/3$. The mass spectrum, based on a symmetry principle, relevant to the problem, is calculated. The result is appropriate for $u$ and $d$ quarks, but differs from experimental values for $c,s, t, b$