of the System of the Universe. 221 
another; and no phenomenon is produced but by analogous 
causes exactly equal to the effect. Thus motion necessarily pro- 
duces motion, and the existence of motion affords proof of the 
existence of a cause in some superior motion. Disturbance is 
always counteracted by the inertia of matter, and the mutual 
contest between the moving agent and the moved patient, causes 
both to turn round the centres of their masses, or round a ful- 
crum, on each side of which the quantities of motion are forced 
to seek equality. 
In the solar system, the sun is the moving power of all the 
planets. Whatever be the origin of its own motions, the suN 
acts, in the ceconomy of the planetary bodies of the solar system, 
like the HEART in the ceconomy of the animal system. Its own 
motion may be created by some arrangement within itself—by 
& perpetual motion of divine contrivance—by the cross and re- 
ciprocal actions of the planets—or, according to an hypothesis 
of Herschel, it may have a superior orbit among systems of suns; 
and our planets and their satellites may be its secondaries and 
sub-secondaries! It will, however, satisfy the spirit of philoso- 
phy, if we can trace all those motions, which have hitherto baf- 
fled inquiry, to the natural action of a primum mobile like the 
sun; and we may be content there to terminate our inquiries, at 
ieast for some ages. Thus much seems certain, that the motions 
of the solar system may be correctly likened to that of a penta- 
graph or polygraph—the planets mimicking the motions of the 
central mass, just as the tracing points mimick those of the ori- 
ginal in the action of that machine; or perhaps the motion of 
_ the sun may be compared to that of the hand, while whirling a 
string with a weight at the end—the hand moving through a 
circle of one or two inches, giving thereby an orbit of several 
yards to the weight at the end of the string. In universal space, 
however, and in performing absolute motion, the planets move 
in no relations like that of the weight to local and relative powers ; 
and therefore have no inclination to fly off in a tangent *! 
* In tracing the effects from their causes, let us suppose the 
solar system to be stationary: let the sun, whose mass is a given 
number of times greater than either of the planets, be moved one 
foot—then will each of the planets be moved in the same direc- 
tion, according to a ratio governed by the positions and bulks. 
of the whole, a certain number of feet, as 100,000, or 1,000,000 
feet, according to circumstances. 
Such a circular motion of a preponderating central mass, act- 
* The dispositions to fly off in a tangent, and fall to the sun, given to 
the planets by the Newtonian philosophy, are gratuitous assumptions, 
which ore almost blushes to name, and are unsupported by any analogy, 
and unwarranted by the universal simplicity of the machinery of nature. 
ing 
