Principles of Electricity by Maynard Shipley

We have already shown how the magnetism of a magnet is converted into electricity, by means of rotating coils cutting the lines of magnetic force in the "field. " The energy used to drive the machinery may, of course, be derived either from water-power or by steam. Gravity gives energy to falling water; chemical energy produced by the oxidation of coal becomes heat energy, which in turn causes the expansion of steam, which produces energy of motion in a piston; and this motion, transmitted to the parts of an engine to a dynamo, produces electrical energy. When the electric current from the dynamo has been conducted to any desired point by cables, another motor, acting in the opposite sense, causes the electricity to change back again into the original mechanical energy, less the loss due to imperfections in the operation. Here we have, then a clear picture of what is meant by the phrase, _transformation of energy_.

But another question naturally arises at this point. We know that with a finite quantity of magnetism we can produce an unlimited quantity of electricity. Yet we add no new material, no source of supply, to the dynamo. Let the rotating coils continue to cut the lines of magnetic force in the magnetic field, and the magnetism of the magnet will be transformed into current electricity-furnishing a literally exhaustless supply from the great storehouse of nature. For us the energy of the universe is infinite in quantity. The reservoir of energy is exhaustless, and the dynamo is man's open sesame.