Franklin made one or two experiments before his renowned kite-flying arrangement, which convinced him that electricity was by no means an agent to be played with. He endeavoured to kill a turkey by electricity, but by incautious handling of the jars in which the “fluid” was stored, he discharged them, and describes the result: “The flash was very great, and the crack was as loud as a pistol; yet my senses being instantly gone, I neither saw the one nor heard the other, nor did I feel the stroke on my hand, though I afterwards found it raised a round swelling where the fire entered as big as half a pistol bullet.” On a subsequent occasion he was again struck senseless while endeavouring to administer a shock to a paralytic patient. It was not until June 1752 that Franklin made the experiment with the kite, which resulted in such great discoveries. He made his kite of a silk pocket-handkerchief, and he fixed a pointed rod upon the upright portion of the frame at the top; the string ended in a foot or so of silk, which was held by the philosopher, and to the end of the hempen portion of the string a large key was tied. For some time, notwithstanding the approach of most unmistakable thunder-clouds, his patience was tried. But at last the strands of the hempen string began to bristle up, and soon after, when Franklin applied his knuckle to the key, a spark was obtained. The great discovery was made. Franklin subsequently obtained lightning in his own house, and performed several experiments with it. [Illustration: Fig. 211.—The Electroscope.] The Electroscope (fig. 211) is an instrument by which we can ascertain whether electricity is present or not, and the nature of it. If we bring an object unelectrified close to the ball or knob on the top of the glass shade, the two needles, or strips of gold-leaf, which are often used, will remain still. But if the body has been electrified it will communicate the electricity to the rod inside, and attract to itself the fluid of opposite quality; the same kind of electricity then is in action in the gold-leaf or needles, and they fly apart—repel each other. Supposing that positive electricity were first communicated, we can cause the contraction of the leaves or wires by applying a negative kind, which, meeting the positive, neutralizes it, and the wires collapse. If the electricity with which the instrument is charged be positive, by approaching the baton to the ball, A, we shall see the wires diverge more than before, and they will finally be discharged by the knobs within. If the electricity be contrary to that in the baton, the wires will approach each other, but by gradually withdrawing the baton they will again separate, and even to a greater distance than before.