electricity is gone at once—dispersed on the instant, in a manner wonderful to think of.
I must now take up a little of your time in showing you the manner in which these powers are transferred from one thing to another; for the manner in which force may be conducted or transmitted is extraordinary, and most essential for us to understand. Let us see in what manner these powers travel from place to place. Both heat and electricity can be conducted; and here is an arrangement I have made to show how the former can travel. It consists of a bar of copper (fig. 42), and if I take a spirit-lamp
Fig. 42.
(this is one way of obtaining the power of heat) and place it under that little chimney, the flame will strike against the bar of copper and keep it
