Page:Cyclopedia of illustrations for public speakers, containing facts, incidents, stories, experiences, anecdotes, selections, etc., for illustrative purposes, with cross-references; (IA cyclopediaofillu00scotrich).pdf/509



turned back over and over again. Indeed, more than good-nature is involved, for the witnesses are in most cases working men, who are making an actual sacrifice, in that they are losing the time that is money to them, and the sleep that is essential to their welfare.—Harper's Weekly.

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Nature—See. NATURE AIDING SCIENCE  The cultivation of certain species of spiders solely for the fine threads which they weave has an important bearing upon the work of the astronomer. No substitute for the spider's thread has yet been found for bisecting the screw of the micrometer used for determining the positions and motions of the stars; not only because of the remarkable fineness of the threads, but because of their durable qualities. The threads of certain spiders raised for astronomical purposes withstand changes in temperature, so that often in measuring sun-*spots they are uninjured when the heat is so great that the lenses of the micrometer eye-pieces are cracked. These spider lines are only one-fifth to one-seventh of a thousandth of an inch in diameter, compared with which the threads of the silk-worm are large and clumsy.—Harper's Weekly.

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Nature Altruistic—See.

Nature and Man—See.

Nature and Prayer—See ;.

NATURE AS A CLUE TO SCIENCE

Man prides himself on his powers and attainments. Has he ever made a rose or produced a mechanism like the hand, or done a thousand things that Nature knows?

As an illustration of Nature's superiority, the electric ray is cited.

The electric ray, or torpedo, has been provided with a battery which, while it closely resembles, yet in the beauty and compactness of its structure it greatly exceeds the batteries by which man has now learned to make the laws of electricity subservient to his will. In this battery there are no less than 940 hexagonal columns, like those of a bees' comb, and each of these is subdivided by a series of horizontal plates, which appear to be analogous to the plates of the voltaic pile. The whole is supplied with an enormous amount of nervous matter, four great branches of which are as large as the animal's spinal cord, and these spread out in a multitude of thread-like filaments round the prismatic columns, and finally pass into all the cells. A complete knowledge of all the mysteries which have been gradually unfolded from the days of Galvani to those of Faraday, and of many others which are still inscrutable to us, is exhibited in this structure.

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NATURE AS A MODEL

The voice of the singer travels forward more abundantly than backward, because he uses the roof, and, to some extent, the walls and floor of his mouth, as a sound reflector. The roof of his mouth being made of concave plates of bone with a thin velarium of integument stretched tightly over them, supplies a model sound-reflector. Every architect who has to build a concert- or lecture-room, or theater, should study the roof of his own mouth, and imitate it as nearly as he can in the roof of his building.

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The analogies which furnish means of expression to the art of building find their models in nature. That which we feel at the sight of an edifice, the artist has felt a hundred times in contemplating the shifting curves of a hill, the bold edge of a haughty peak, the immensity of an even plain, a ground hollow, or gently undulating sheet of water which loses itself in the mists of the horizon. All the effects produced by architecture are only an interpretation of natural ones. What is a pyramid? A hollow cavern in a mountain. What is a Greek temple with its porticoes and columns? A memory of the sacred woods where were drest the first altars. What do we feel in entering a Gothic cathedral? The shudder felt at the divine awfulness of the forests. And it is also from the natural world that architecture has taken its decorations. Columns and capitals, rosettes, flowers intertwinings, ovals, foliage medallions, all remind us of something seen in the fields and in the woods, in plants and animals.—, Revue des deux Mondes.

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See.