LAWS OF GOD IX XATUEE. 
15 
turn to the laws which govern light, the laws of radiation, re¬ 
flection, refraction, and colour. These all admit of arithmetical or 
geometrical expression. That is to say, using the word law, firstly, 
in its ordinary meaning of that which is laid or fixed or decreed 
respecting things or respecting phenomena, and secondly, as a name 
for the written mathematical expression of that which is laid or 
fixed or decreed in terms of number or time or space, we say 
first that it has been decreed—-by superhuman authority—that the 
phenomenon of light shall possess the attributes of radiation, 
reflection, and refraction, and secondly, that these attributes shall 
be exerted in so regular and simple a manner that man shall have 
the power of discovering or unveiling them, and of describing them 
with mathematical precision. Law 1,—light radiates in straight 
lines and in every direction from any light-giving body. Imagine 
many hundreds of pieces of string stretched from a single point in 
the centre of a room downwards to every small space (say, every 
square foot) on the floor, upwards to every similar space 
on the ceiling, and sideways to every similar space on each of 
the walls, the strings all being straight and rigid, like the spines 
of a rolled-up hedgehog or “ like quills upon the fretful porcupine.” 
Those strings thus stretched from that centre roughly represent the 
manner and direction in which light radiates from a luminous 
centre, he that centre the flame of a rushlight, the arc of an electric 
lamp, our own beautiful moon, our glorious sun, or any one 
of those not less lovely stars that ever stud our sky. The light- 
strings or pencils or rays are, however, infinite in number, and 
are capable of travelling infinite distances, the few which come 
to this earth from the sun having travelled more than ninety 
millions of miles; while the enormous numbers that fly past our 
earth, or which are projected in all other directions from the sun, 
may travel many times that distance before they impinge on any 
heavenly body. JSTot only is the direction in which light travels 
definite, but (law 2) its velocity also is definite, being more than 
ten millions of miles a minute; the light of the sun taking rather 
more than eight minutes to reach us, while that of other suns or 
stars takes many years, so distant are they. Then, with regard to 
a third law of radiation, everybody knows that when we work 
or read by artificial light, we can see better if the lamp or candle is 
fairly near to the work or book than if it is some distance away; 
hut what perhaps many of us have not realised is that as we recede 
further and further from the source of the light, the diminution in 
the amount of light goes on according to a simple law, namely, in 
inverse proportion to the square of the distance. That is to say, 
