"Hence a wet rat cannot be killed by the exploding electrical bottle, when a dry rat may."
In a letter of 1750, based upon observations made in 1749, Franklin said distinctly, after describing some artificial lightning which he had made:—
"If these things are so, may not the knowledge of this power of points be of use to mankind, in preserving houses, churches, ships, &c., from the stroke of lightning, by directing us to fix, on the highest parts of these edifices, upright rods of iron made sharp as a needle, and gilded to prevent rusting, and from the foot of those rods a wire down the outside of the building into the ground, or down round one of the shrouds of a ship, and down her side till it reaches the water? Would not these pointed rods probably draw the electrical fire silently out of a cloud before it came nigh enough to strike, and thereby secure us from that most sudden and terrible mischief?
"To determine the question whether the clouds that contain lightning are electrified or not, I would propose an experiment to be tried where it may be done conveniently. On the top of some high tower or steeple, place a kind of sentry-box, big enough to contain a man and an electrical stand. From the middle of the stand let an iron rod rise and pass bending out of the door and then upright twenty or thirty feet, pointed very sharp at the end. If the electrical stand be kept clean and dry, a man standing on it, when such clouds are passing low, might be electrified and afford sparks, the rod drawing fire to him from a cloud. If any danger to the man should be apprehended (though I think there would be none), let him stand on the floor of his box, and now and then bring near to the rod the loop of a wire that has one end fastened to the leads, he holding it by a wax handle; so the sparks, if the rod is electrified, will strike from the rod to the wire, and not affect him."
The Royal Society "did not think these papers worth printing"!
But, happily, Collinson printed them, and they went all over Europe. The demonstration of the lightning theory, which he had wrought out by his own experiments, was made in France, May 10, 1752; and in Philadelphia by Franklin with the kite in the next month, before he had heard of the success in France. Franklin's friend Dalibard tried the French experiment. Here is his account of it, as he sent it to the French Academy, as Roxana translated it for the young people:—
I have had perfect success in following out the course indicated by Mr. Franklin.
I had set up at Marly-la-ville, situated six leagues from Paris, in a fine plain at a very elevated level, a round rod of iron, about an inch in diameter, forty feet long, and sharply pointed at its upper extremity. To secure greater fineness at the point, I had it armed with tempered steel, and then burnished, for want of gilding, so as to keep it from rusting; beside that, this iron rod is bent near its lower end into two acute but rounded angles; the first angle is two feet from the lower end, and the second takes a contrary direction at three feet from the first.
Wednesday, the 10th of May, 1752, between two and three in the afternoon, a man named Coiffier, an old dragoon, whom I had intrusted with making the observations in my absence, having heard rather a loud clap of thunder, hastened at once to the machine, took the phial with the wire, presented the loop of the wire to the rod, saw a small bright spark come from it, and heard it crackle. He then drew a second spark, brighter than the first and with a louder sound! He called his neighbors, and sent for the Prior. This gentleman hastened to the spot as fast as he could: the parishioners, seeing the haste of their priest, imagined that poor Coiffier had been killed by the thunder; the alarm was spread in the village; the hail-storm which began did not prevent the flock from following its shepherd. This honest priest approached the machine, and, seeing that there was no danger, went to work himself and drew strong sparks. The cloud from which the storm and hail came was no more than a quarter of an hour in passing directly over our machine, and only this one thunder-clap was heard. As soon as the cloud had passed, and no more sparks were drawn from the iron rod, the Prior of Marly sent off Monsieur Coiffier himself, to bring me the following letter, which he wrote in haste:—