1884. 89 Trans. N. V. Ac. Sci. 



at all gradual, would produce no visible effect. All it could do was to 

 affect the length of days and nights, and, consequently, introduce 

 seasons. These changes, if they occurred, would have registered 

 themselves in changes in the plants and animals of high latitudes ; 

 while in low latitudes no perceptible effect would have been produced, 

 and, consequently, the species would continue as they were before. 

 Geology teaches very clearly that in high latitudes there did occur 

 toward the end of the geological record a complete disappearance of 

 old species, while in low latitudes they were unaffected. 



The conclusion toward which these facts point would be readily ac- 

 cepted, were it not for reasons derived from another source than 

 geology. Astronomers say that a permanent change in the inclination 

 of the earth's axis is impossible, so far as any force is concerned which 

 is known to science. But, as this is equally true of many other things 

 which have actually been done, it is not an insuperable objection. 

 " No force known to science " can vivify matter, yet living beings are 

 all around us. 



There are only two theories as to the existence of our world. The 

 one attributes it to an Omnipotent Intelligence, that, for His own pur- 

 poses, made the universe, and, by His wisdom and power, brought it 

 through stages of development, some of which we have been able to 

 recognize, and some so far to understand as to class them with others, 

 and then, having named the order in which the events are arranged, 

 call it " law," and sometimes think we have thereby comprehended it. 



The only theory of the solar system on mechanical principles is the 

 nebular hypothesis in its several forms. In all, the earth and moon 

 were once one body, revolving, of course, on one axis. At some 

 remote time they separated. But no force of avulsion, whether the 

 moon was left behind as the mass contracted, or whether, as has been 

 more lately held, it was thrown off by the great centrifugal force after 

 the earth had become solid, and then was gradually pushed back by 

 the influence of the friction of the tidal wave, could affect the plane 

 of rotation or the direction of the axis of either. On mechanical 

 principles, the moon, when it left the earth, moved in the plane of the 

 earth's equator, and the axis of the earth and the moon and of its 

 orbit were parallel to each other. The normal position of the three 

 was perpendicular to the ecliptic. But now the axis of the moon is 

 inclined 1^°, and that of the earth 23!°. Very evidently, either the 

 earth's axis or the moon's has changed. The moon's axis is now 

 nearly in the normal position. Hence I conclude that it was the 

 earth's axis that changed. 



Astronomy, therefore, proves too much. It proves that the present 

 condition is not eternal, that normally the axis was perpendicular to 



