I thought Coulomb's law was just a special case of gauss law.
I am pretty sure they had to have had used something to measure the charge of an object and its flux to come up with the permittivity constant and etc.
Gauss equations state that the flux of a gaussian surface is equal to the sum of all the electric field times the surface area.
Although he stated this in theory, how was he able to prove it possible. What measuring device do people use to prove that this theory is correct?