⁽⁶⁾Ohm’s law was published in 1861, so the first transatlantic cable was a little bit the proverbial cart before the horse. Indeed, the cable circuit formed an enormous RC equivalent circuit, i.e. a big lowpass filter, so that the sharp rising edges of the Morse symbols were completely smeared in time. The resulting intersymbol interference was so severe that it took hours to reliably send even a simple sentence. Not knowing how to deal with the problem, the operator tried to increase the signaling voltage (“crank up the volume”) until, at 4000 V, the cable gave up.