A copy of this photograph had been sent to Einstein from England, and he told me of it with evident pleasure. He continually reverted to the delightful little picture of the heavens, quite fascinated by the thing itself, without the slightest manifestation of a personal interest in his own success. Indeed, I may go further and am certainly not mistaken in saying his new mechanics did not even enter his head, nor the verification of it by the plate; on the contrary, he displayed that disposition of the mind which in the case of genius as well as in that of children shows itself as _naïveté_. The prettiness of the photograph charmed him, and the thought that the heavens had been drawn up as for parade to be a model for it. All things are repeated in the history of life. In these happenings, which mark the 29th May 1919 as a red-letter day in the history of science, we recognize a revival of the Sun Myth, unperceived by the individual, but as an expression of the universal consciousness, just as when Copernicus converted the geocentric picture of the universe into a heliocentric one, the Sun Myth again sprang into life; the symbolization of faith in the light-giving and heat-giving star. This time it has arisen, purified of all dross, scarcely perceptible to our senses, like an aureole spun about the sun by far-distant sources of light, in honour of a principle, and even if most of us do not yet know what a "system of reference" means, yet for many such a system has unconsciously evolved, a thought-system serving as a reference for the development of their knowledge when they thought or spoke of Einstein. CHAPTER II BEYOND OUR POWER Useful and Latent Forces.--Connexion between Mass, Energy, and Velocity of Light.--Deriving Power by Combustion.--One Gramme of Coal.--Unobtainable Calories.--Economics of Coal.--Hopes and Fears.--Dissociated Atoms. _29th March_ 1920 WE spoke of the forces that are available for man and which he derives from Nature as being necessary for his existence and for the development of life. What forces are at our disposal? What hopes have we of elaborating our supply of these forces?