A-B-C of Electricity

by Wm. H. Meadowcroft

We will explain these in their order.

Fig. 1

The Volt.—This term may be better understood by making a comparison with something you all know of. Suppose we have a tank containing one hundred gallons of water, and we want to discharge it through a half-inch pipe at the bottom of the tank. Suppose, further, that we wanted to make the water spout upward, and for this purpose the pipe was bent upward as in Fig. 1.

If you opened the tap the water would spout out and upward as in Fig. 1.

Fig. 2

The cause of its spouting upward would be the weight or pressure of the water in the tank. This pressure is reckoned as so many pounds to the square inch of water.

Now, if the tank were placed on the roof of the house and the pipe brought to the ground as shown in Fig. 2, the water would spout up very much higher, because there would be many more pounds of pressure on account of the height of the pipe.

So, you see, the force or pressure of water is measured in pounds, and, therefore, a pound is the unit of pressure, or force, of water. Now, in electricity the unit of pressure, or force, is called a volt.