Equations three and four from Maxwell's Equations combine into the form of a wave
equation and Maxwell calculated the speed at which such a wave would travel.
Recognising a good approximation to the speed of light he said "This velocity is so
nearly that of light, that it seems we have strong reason to conclude that light itself
(including other radiations if any) is an electromagnetic disturbance in the form of
waves propagated through the electromagnetic field"
Thus Maxwell is also credited with predicting the existence of a wide range of such
"Electromagnetic Waves" - a spectrum we now use as radio, radar and microwaves etc
and which connect us all "in time of light" (i.e. at light speed) - and Maxwell's
Equations have been called "the Hidden Heartbeat of the modern world".