here and here."During that period a very great number of induction coils and circuit-breakers were announced, but no importance or interest seems to have been attached to this branch of the subject. We had the Masson coil, the Neef coil, the Callan coils, the Sturgeon coils, the McGauley coil, the Dr. Bird coil, the Lockey, the Nesbitt, the Clarke, the Roberts, the Bachhoff'ner, and many other coils, all represented as being very potent in giving shocks; but, beyond the intensity required for this purpose, not a single inquiry is recorded."
But like the others, the first thing he set about doing was shocking himself. He connected a battery to both ends of the primary coil. He discovered that when the battery contact was broken, a shock could be felt between the first terminal of the primary coil and the unconnected end of the secondary coil. But he did something interesting with it. He engineered a way to break and reconnect that circuit quickly with a device he called a "repeater." He used a hand crank that turned a cog wheel that connected to a horizontal copper rod via an escapement that made connection with the wheel. With it he was able to break and make the circuit over 500 times a second. This generated some massive sparks. He experimented with more and more powerful battery configurations until his peers were afraid of his works. He described it in the 1836 July-December issue of the London and Edinburgh Journal of Science.
"By experiments on the best means of obtaining the shock from the electromagnet, I have found that the shock increases, within certain limits, with the length and thinness of the bar of soft iron, and with the length of the helical coil, as far perhaps as 200 feet, and in proportion, or nearly in proportion, to the number of plates in the voltaic battery from which the current of electricity is passed through the helix. The shock does not increase in proportion to the number of plates unless they are large. ... the shock was so strong that a person who took it felt the effects of it for several days. ... I could not induce any one to take the shock from the electromagnet when a greater number than 16 of our large plates were used."Later Callan's experimented with an induction coil using toughs of mercury just like Page. His was arranged with a wire that was rocked repeatedly into the mercury. Ultimately Callan determined (at least tactility) that the faster he interrupted the current, the bigger the spark. In 1837 he build a large scale induction device It generated 15-inch sparks, which are estimated to have produced up to 600,000 volts which was the largest artificial bolt of electricity ever made.
Despite the reception of his 1837 paper, he did not publish often. And because his college was a theological school, his colleagues often tried to dissuade him in science pursuits. He experimented with galvanization and different batteries but did gradually stray away from his greatest contributions. He died in 1864, about 40 years before he'd be recognized scientifically for his contributions.