THE ETHER IS GRAVITATIONLESS.
One might infer already that if the ether were structureless, physical laws operative upon such material substances as atoms could not be applicable to it, and so indeed all the evidence we have shows that gravitation is not one of its properties. If it were, and it behaved in any degree like atomic structures, it would be found to be denser in the neighbourhood of large bodies like the earth, planets, and the sun. Light would be turned from its straight path while travelling in such denser medium, or made to move with less velocity. There is not the slightest indication of any such effect anywhere within the range of astronomical vision.
Gravitation then is a property belonging to
matter and not to ether. The impropriety of thinking or speaking of the ether as matter of any kind will be apparent if one reflects upon the significance of the law of gravitation as stated. Every particle of matter in the universe attracts every other particle. If there be anything else in the universe which has no such quality, then it should not be called matter, else the law should read: Some particles of matter attract some other particles, which would be no law at all, for a real physical law has no exceptions any more than the multiplication table has. Physical laws are physical relations, and all such relations are quantitative.
7. MATTER IS FRICTIONABLE.
A bullet shot into the air has its velocity continuously reduced by the air, to which its energy is imparted by making it move out of its way. A railway train is brought to rest by the friction brake upon the wheels. The translatory energy of the train is transformed into the molecular energy called heat. The steamship requires to propel it fast, a large amount of coal for its engines, because the water in which it moves offers great friction—resistance which must be overcome. Whenever one surface of matter is moved in contact with another surface there is a resistance called friction,
the moving body loses its rate of motion, and will presently be brought to rest unless energy be continuously supplied. This is true for masses of matter of all sizes and with all kinds of motion. Friction is the condition for the transformation of all kinds of mechanical motions into heat. The test of the amount of friction is the rate of loss of motion. A top will spin some time in the air because its point is small. It will spin longer on a plate than on the carpet, and longer in a vacuum than in the air, for it does not have the air friction to resist it, and there is no kind or form of matter not subject to frictional resistance.
THE ETHER IS FRICTIONLESS.
The earth is a mass of matter moving in the ether. In the equatorial region the velocity of a point is more than a thousand miles in an hour, for the circumference of the earth is 25,000 miles, and it turns once on its axis in 24 hours, which is the length of the day. If the earth were thus spinning in the atmosphere, the latter not being in motion, the wind would blow with ten times hurricane velocity. The friction would be so great that nothing but the foundation rocks of the earth's crust could withstand it, and the velocity of rotation would be reduced appreciably in a relatively short time. The air
moves along with the earth as a part of it, and consequently no such frictional destruction takes place, but the earth rotates in the ether with that same rate, and if the ether offered resistance it would react so as to retard the rotation and increase the length of the day. Astronomical observations show that the length of the day has certainly not changed so much as the tenth of a second during the past 2000 years. The earth also revolves about the sun, having a speed of about 19 miles in a second, or 68,000 miles an hour. This motion of the earth and the other planets about the sun is one of the most stable phenomena we know. The mean distance and period of revolution of every planet is unalterable in the long run. If the earth had been retarded by its friction in the ether the length of the year would have been changed, and astronomers would have discovered it. They assert that a change in the length of a year by so much as the hundredth part of a second has not happened during the past thousand years. This then is testimony, that a velocity of nineteen miles a second for a thousand years has produced no effect upon the earth's motion that is noticeable. Nineteen miles a second is not a very swift astronomical motion, for comets have been known to have a velocity of 400 miles a second when in the neighbourhood of the sun, and yet they have not