From [Wikiwand: Maxwell (unit)](https://www.wikiwand.com/en/Maxwell_(unit)):

>This practical unit was previously called a line,[4] reflecting Faraday's conception of the magnetic field as curved lines of magnetic force,[5] which he designated as *line of magnetic induction*.[4] *Kiloline* ($10^3$ line) and *megaline* ($10^6$ line) were sometimes used because 1 line was very small relative to the phenomena that it was used to measure.

So how is a “line” measured? Does anyone have specifics on this measurement?