While a rocket trailing a conducting wire may or not trigger lightning studies at the University of Toronto in 1978, two years after its erection. In 1989, a new phase of the CN Tower lightning observations were operational to simultaneously measure seven of the most relevant lightning parameters: the current, the vertical component of the electric field and two horizontal components of the magnetic field (detected 2 km north of the Tower), the return-stroke velocity, and two VHS lightning trajectory records taken from almost perpendicular directions [1]. The most valuable of these parameters is the lightning current. This is because of the general difficulty of measuring the lightning current,