UNDER THE MAPLES 



than like a rigid insensate sphere. Its surface 

 throbs and palpitates and quivers and yields to 

 pressure as only living organisms do. The tides can 

 hardly be regarded as evidences of its breathing, as 

 Kepler thought they could, but they are proof of 

 how closely it is held in the clasp of the heavenly 

 forces. It is like an apple on the vast sidereal tree, 

 that has mellowed and ripened with age. Our moon 

 is no doubt as dead as matter can be. It is hard to 

 fancy its surface yielding to our tread as does that 

 of the earth. Then we know that the absence of 

 air and water on it is proof that it cannot be 

 endowed with what we call life. George Darwin 

 tells us that when we walk on the ground we warp 

 and bend the surface very much as we might bend 

 or dent the epidermis of a colossal pachyderm. 

 He and his brother devised an instrument by which 

 the slight fluctuations of the ground, as we move 

 over it, could be measured. The instrument was 

 so delicate that it revealed the difference of effect 

 produced by the same pressure at seven feet and 

 at six feet from the instrument! More than that, 

 the instrument revealed the throbbing and agita- 

 tions which the ground is undergoing at all times. 

 They found that minute earthquakes, or micro- 

 seisms, as the Italians call them, are occurring con- 

 stantly. 



Another instrument has been invented called the 

 microphone, which translates this earth's move- 



170 



