So, too, the writer remembers having an interest in mineralogy awakened in his mind, never to be obliterated, by the sight of another plowed field, in the southern skirts of the Adirondack Mountains, whose freshly turned furrows glittered in the sunshine with thickly scattered quartz crystals, some of the larger and more perfect of which blazed across, the whole breadth of the field, like huge diamonds, and made the heart of the finder beat with an excitement akin to that of the discoverer of a Koh-i-noor. There were also some very curious "stone buttons" which one could break out with a hammer from slate rocks along the Schoharie Creek, and which, when cracked open, were found to be composed of pyrites that resembled pure silver--and sometimes gold--freshly broken. Now, things of this sort are always attracting the attention and awakening the curiosity of children living in the country, but the real pleasure and instruction that they might afford are usually missed because of the lack in the family library of popularly written books on the natural sciences--a lack that we are trying to supply. For city children and their elders, whose eyes are constantly greeted, not by hills, creeks, ponds, rivers, woods, and fields, but by sky-aspiring buildings, railroads elevated on stilts, multiple-decked suspension bridges, electric power houses, tunnels that form a second city underground, and the thousand marvels and splendors of electric illumination at night, the volumes on physics, mechanics, and electricity and magnetism have a more immediate interest and value. What the children learn about these things in school is far from sufficient to satisfy their curiosity. They need books at home to guide their inquiries as well as to answer them. Only by that means can the diffusion of scientific knowledge, and the popularization of the scientific method of getting at the truth and the meaning of things be thoroughly effected. Science, as its history plainly demonstrates, progresses most rapidly only when a great number of minds have been led to concentrate their powers upon its problems. Great genius, it is true, rides over obstacles; yet consider how much further its energies might have carried it if the obstacles had been more or less completely removed in advance. Many a young man has been led to a brilliant career, to the great advantage of his country and his time, as a result of the interest awakened in him by the clear statements of a popularly written book on some branch of science.