Modern Science : A Criticism 



ing to the North Star. In the one case you are 

 tending to a speedy conclusion of your labours, 

 in the other case you are only going in a certain 

 direction. The theories of Science generally belong 

 under the second head. They mark the direction 

 which the human mind is taking at the moment 

 in question, but they mark no limits. At each 

 point the appearance of a limit is introduced which 

 becomes, like a mirage in the desert, an object 

 of keen pursuit ; but the limit is not really there 

 it is only an effect of the standpoint, and disap- 

 pears again after a time as the observer moves. 

 In the case of gravitation there is for the moment 

 an appearance of finality in the law of the inverse 

 square of the distance, but this arises probably 

 from the fact that the law is derived from a limited 

 area of observation only, namely the movements 

 (at great distances from each other) of some of the 

 heavenly bodies. 1 The Cavendish and Schehallien 

 experiments do not show more than that the law 

 at ordinary distances on the earth's surface does 

 not vary very much from the above ; while the so- 



1 It is not generally realised how feeble a force gravitation is. 

 It is calculated (Encycl. Brit., Art. Gravitation) that two masses, 

 each weighing 415,000 tons, and placed a mile apart, would exert 

 on each other an attractive force of only one pound. If one, 

 therefore, was as far from the other as the moon is from the earth, 

 their attraction would only amount to gy 6oo ^ 000 th of a pound. 

 This is a small force to govern the movement of a body weighing 

 415,000 tons ! and it is easy to see that a slight variation in the 

 law of the force might for a long period pass undetected, though 

 in the course of hundreds of centuries it might become of the 

 greatest importance. 



