66o 
Mr. S. Butler’s Contributions to the [November, 
everything to its centre ; but the Earth itself would remain 
stationary. I have thus accounted for centripetal force : 
now where shall we look for centrifugal force ? 
It is plain that, if the Earth’s radiations were not per- 
fectly equal all around, it would recede in the opposite 
direction to where they were strongest. Then comes the 
part the Sun does. The heat of the Sun destroys the 
evenness of the Earth’s radiations by giving extra food for 
radiation, now at one part and again at another, thus giving 
it a forward motion without materially affeCting its centri- 
petal force. 
We have only to look at the circular motion a billiard ball 
describes when struck on the side by an expert, or tbe ellip- 
tical orbit pursued by a ball on the bowling alley, when 
thrown by a master hand, or even the peculiar course fol- 
lowed by the boomerang as it speeds along, its different 
sides ever changing their relation to the surrounding atmo- 
sphere. 
We have only to look at these to get at least a vague idea 
how the Earth describes a circle by means of its varied 
radiations. While the reacting force of the planets’ radia- 
tions perform the functions above described, their radiations 
have a part to perform. These radiations prevent them 
coming into collision by repelling each other. 
Thus we see the wisdom of the Creator, who doeth all 
things well. The bodies of the universe are ail a piece of 
perfect machinery, made by a master hand, and do not 
require to be watched or wound up to keep it in order. 
VI. MR. S. BUTLER’S CONTRIBUTIONS TO 
THE QUESTION OF EVOLUTION. 
UR readers may remember that we have on former 
occasions noticed some of the works of Mr. S. Butler 
— too favourably if we may judge from certain 
letters of remonstrance which we have received. The time 
has now come when an estimate of his services or dis- 
services, as regards the great theory of Evolution, may be 
fairly attempted. 
