Let a metallic plate, _a_, Fig. 265, be suspended by a chain to the prime conductor, and another plate, _b_, be supported upon a conducting stand. If figures of paper or pith be placed between these plates as the machine is worked they will move about briskly between the plates, being alternately attracted and repelled by the communication of the electricity. [Illustration: Fig. 266.] The experiment represented in Fig. 266 is a very beautiful one. Let _a b_ be a brass rod with an arch, _g_, by which it can be suspended from the end of the prime conductor. To this rod are suspended three bells, the two outer ones by chains, and the middle one by a silk thread; also two clappers, _d_ and _e_, by silk threads. The middle bell has a chain, _f_, connecting it with the table--that is, with the earth. The operation of the apparatus is this: As soon as the outer bells become electrified they attract the clappers. These, on touching the bells, receive a portion of their electricity, and are repelled. They therefore strike against the middle bell, to which they impart the electricity which they received from the outer bells. They swing back again then in the same state that they were in at first, and now are attracted again by the outer bells. This goes on so long as the electricity is communicated. [Illustration: Fig. 267.] Let there be pasted upon a slip of glass a continuous line of tin-foil, going back and forth, as represented in Fig. 267, and let there be a ball, G, connected with one end of, the foil. The word light is made upon it by cutting out with a sharp knife little portions of the foil. If now with your finger on one end of the line of foil at _a_, you present the ball G to the prime conductor, the electric fluid will run along the whole length of the line from G to _a_. In doing this the letters are beautifully illuminated, a spark being produced at each interruption of the line. So rapid is the passage of the electricity that the whole appears to the eye simultaneously illuminated. [Illustration: Fig. 268.] 382. =The Insulating Stool.=--This consists of a wooden top, _a_, Fig. 268, supported by glass legs, _c c_. It can be made simply by boring holes in the four corners of a piece of board sufficiently large to admit the necks of bottles. Many amusing experiments can be tried with this. A person standing upon it can be highly charged with electricity by holding a chain connected with the prime conductor. The hair will rise up as represented in Fig. 263, and he can give electric shocks to other persons from any part of his body. [Illustration: Fig. 269.]