Page:Handbook of Meteorology.djvu/22



Ether and Matter.—It is not necessary to assume that the universe and space are one and the same; nor that the universe is boundless; nor that space is without limits. So far as that part of the universe with which human knowledge comes in contact is concerned, the existence of two factors is assumed. Matter is perceptible to the human senses. It is visible, tangible, and transformable. It can be measured and compared; some, at least, of its properties are known. Its ultimate constitution, however, is not known. It is usually described in terms of atoms, molecules and masses.

In certain respects, more is known about ether than about matter: for although the existence of ether is merely assumed, the magnitudes attributed to it are real values that have been fully established. That the universe is pervaded by an invisible, intangible, but measureable something is conceded. It is assumed that the manifestations to the senses known as heat, light, magnetism, electricity, and radiant energy traverse the known part of the universe by the means of the ether. It is not improbable that these manifestations are undulations of the ether itself.

The telescope and the spectroscope have shown that the matter entering into the composition of other visible bodies in the universe does not differ from that which composes the