1. velocity ratio A term applied to the ratios existing between the electrostatic and electro-magnetic units. If we take as numerators the dimensions of the different qualities in the electrostatic system, and their dimensions in the electro-magnetic system as denominators, the fractions thus obtained reduce to expressions containing only velocity or V in some form. Thus if we divide the dimensions of the electrostatic quantity by the dimensions of electro-magnetic quantity the quotient is simply V or velocity. A like division for potential, electrostatic and electro-magnetic gives (1/V), and so on.
The value of the velocity ratio is very nearly 3E10 (sometimes given as 2.98E10) centimeters per second. This is almost exactly that of light (2.9992E10 centimeters per second.) This is one of the proofs of Clerk Maxwell's magnetic theory of light. (See Maxwell's Theory of Light.)
[Transcriber's note: The SI metre was defined in 1983 such that the speed of light in a vacuum is exactly 299,792,458 metres per second or about 186,282.397 miles per second.]
Definitions of velocity ratio
