The answer also includes a link that shows many other representations including Einstein's "4d generally covariant tensor calculus".
The point is that the most common formulation today is not the one Maxwell made (with 12 equations). The idea is preserved, but it was Gibbs and Heaviside that formulated the current 4 equation representation.
https://hsm.stackexchange.com/questions/8173/did-maxwell-ori...
The answer also includes a link that shows many other representations including Einstein's "4d generally covariant tensor calculus".
The point is that the most common formulation today is not the one Maxwell made (with 12 equations). The idea is preserved, but it was Gibbs and Heaviside that formulated the current 4 equation representation.