1901 - 2 .] Mr J. Fraser on Constitution of Matter and Ether-. 47 
ingenious pieces of natural mechanism, if I may call it so, con- 
ceivable, — a sort of self-winding clock, which can go for ever, 
without the slightest loss or gain of motion, — in fact, I believe the 
only perpetual motion machine in existence. Although it has a 
sort of artificial flavour, yet every astronomer will recognise at a 
glance its truth to nature. It is a fact well known to all astrono- 
mers, that the motion of a planet increases as it approaches the sun. 
In the language of the text-books, as the distance decreases, the 
attraction increases inversely as the square of that distance ; and 
consequently the velocity increases inversely as the square root of 
the distance. If, in the above sentence, we substitute the word 
“pressure” for “attraction,” it will be made applicable to the 
present theory. Well, then, as the pressure on an atom increases 
owing to its motion through the ether, the velocity of the particles 
of which it is composed also increases in the ratio of the square 
root of the pressure, the particles on the front of each atom, or 
bubble, being depressed by the resistance of the ether to motion. 
This depression is analogous to the depression of a planet towards 
the sun by an increase of his so-called attracting power, the result 
in both the case of the planet and particle being an increase of 
velocity. Well, then, in the case of the planet, this increase of 
velocity is sufficient, after perihelion, to carry it back to aphelion 
against the resistance of the sun’s gravity ; and in the case of the 
particle, it is sufficient to clear the ether out of its path by in- 
creased centrifugal tendency, — in both cases the effect being just 
equal to the cause. In other words, in both cases the increased 
pressure is producing an increase of velocity which just balances 
the increased pressure : so that the planet can rise to the height 
from which it fell, and the atom can continue its motion indefin- 
itely. 
To meet possible objections, I should like to point out that the 
radiations impinging on the front of the atom will be strengthened 
by its motion, and those impinging on its rear will be corre- 
spondingly weakened, so that these two circumstances cancel one 
another, the increase of motion in the particles caused by the 
strengthening of the radiations being destroyed by the decrease 
caused by their weakening. So that there only remains to be 
considered the increase of pressure caused by the inertia of the 
