These functions are familiar to everybody. From the knowledge of other physical, mechanical and chemical phenomena of nature, we must come to the conclusion, that this human battery is the most perfect example of a complex engine; it has all the peculiarities of a chemical battery combined with a generator of a peculiar energy called life; above all, it has mental or spiritual capacities; it is thus equipped with both mental and mechanical means for producing work. The parts and functions of this marvelous engine have been the subject of a vast amount of research in various special branches of science. A very noteworthy fact is that both the physical work and the mental work of this human engine are always accompanied by both physical and chemical changes in the structure of its machinery—corresponding to the wear and tear of non-living engines. It also presents certain sexual and spiritual phenomena that have a striking likeness to certain phenomena, especially wireless phenomena, to electricity and to radium. This human engine-battery is of unusual strength, durability and perfection; and yet it is very liable to damage and even wreckage, if not properly used. The controlling factors are very delicate and so the engine is very capricious. Very special training and understanding are necessary for its control. The reader may wish to ask: What is the essence of the time-binding power of Man? Talk of essences is metaphysical—it is not scientific. Let me explain by an example. What is electricity? The scientific answer is: electricity is that which exhibits such and such phenomena. Electricity means nothing but a certain group of phenomena called electric. We are studying electricity when we are studying those phenomena. Thus it is in physics—there is no talk of essences. So, too, in Human Engineering—we shall not talk of the _essence_ of time-binding but only of the phenomena and the laws thereof. What has led to the development of electric appliances is knowledge of electrical phenomena—not metaphysical talk about the electrical essence. And what will lead to the science and art of Human Engineering is knowledge of time-binding phenomena—not vain babble about an essence of time-binding power. There is no mystery about the word time-binding. Some descriptive term was necessary to indicate that human capacity which discriminates human beings from animals and marks man as man. For that use—the appropriateness of the term time-binding becomes more and more manifest upon reflection.