94 THE GRAND CENTRE OF THE UNIVERSE. 
the earth, and hence invisible since no reflected light 
~ could make it visible at that distance. 
But there is another force not detected by the eye, yet 
omnipresent, that would render manifest the existence 
of such a body, I mean the attraction which it would 
exert upon neighboring stars. A world in the centre of 
the Pleiades, massive enough to control our sun and 
force it into an orbit in which it moves at the rate of 
four miles a second, would cause its immediate neigh- 
bors to revolve with such inconceivable velocity that 
only a few years would be necessary to make its existence 
evident. No such movements can be detected, hence no 
such body exists. 
Many who will readily accept all that has thus far been 
said, will be slow to believe that the sun, if revolving at 
all, which is scarcely questionable, revolves around a 
mere mathematical point, something which has neither 
length, breadth nor thickness, but position only ; and 
that this point is many thousand million miles distant 
from any star, or, in other words, that the sunis describ- 
ing its inconceivably great orbit around a mere point in 
empty space; 7. e., around nothing at all. Yet such is 
the fact. 
A very little consideration will serve to make this 
clear. Suppose, fora moment, that the only bodies in 
the universe were the sun and the nearest fixed star, and 
that these were of the same mass. Then, if they had a 
sufficient motion in a direction perpendicular to the line 
connecting them, they would move, not one around the 
other, but both around their common center of gravity, 
something as a pair of dumb bells, or two balls on oppo- 
site ends of a string. We have all seen how the string” 
is drawn taut, and the two balls revolve around some 
point between them, a point whose distance from each is 
inversely as the masses. 
In case of the star and our sun, if the masses were 
a4 
