LAWS OF GOB IF FATTTRE. 
11 
act, may commonly be expressed in some simple mathematical 
statement. Take, for example, the law of gravitation. We look 
at the sky on a cloudless night, and our first impression is that we 
are gazing at a star-studded roof or plane, looking at lamps in the 
dome of nature’s cathedral. Bemembering, however, that the 
earth is daily rotating on an axis, that a moon revolves around the 
earth, and the earth around the sun accompanied by some of those 
stars or, rather, planets, that at first sight seemed to he fixed in the 
great dome ; and reflecting on some similar well-ascertained truths, 
as, for instance, that the so-called blueness of the sky is merely 
the blue colour of the air immediately surrounding our little globe : 
considering these facts, we begin to realise what patient workers 
at truth have long ago found out, namely, that the earth and her 
sister planets, though many millions of miles from each other and 
from their central sun, yet form hut one small sun-group amongst 
vast numbers of sun-groups, the groups being scattered through 
illimitable space. Scattered heterogeneously? No. The prime 
law of order everywhere prevails. The position and motion of one 
planet affects, more or less, the position and motion of every other, 
while, doubtless, every orb in the universe is similarly influenced, 
each being attracted by each, and all being governed, not by myriads 
of laws of attraction, but by one law, namely, that of gravitation, the 
extent or power of which is expressed in the simple statement that 
it acts directly as the mass and inversely as the square of the distance . 
What gravitation is in its inner essence we know not. We know 
it only as we know any force, by its effects. But it governs the 
fall of an apple and the flight of birds or insects in the same 
simple manner that it guides the rush of Jupiter and the move¬ 
ments of the sun itself. Call it a decree passed respecting all 
matter, call it a law, call it a force, call it what you will, gravita¬ 
tion, and the principle just expressed mathematically respecting 
the manifestation of gravitation, are great all-reaching stupendous 
truths, yet simple all-perfect beautiful truths of nature. It has 
been decreed that material substances shall be indestructible, it has 
been decreed that material substances shall attract and be attracted 
in definite proportions. The statement as to the proportions may 
he termed a law, gravitation itself and other forces may be regarded 
as law, but, from the present point of view, it is the decrees 
respecting those material substances and those forces that are the 
prime laws as mankind generally regard laws. Who decreed these 
laws ? Not man. 
From the centripetal law of gravitation which governs the 
tendency of our earth to be attracted towards the sun, we might 
