io8 KANT'S UNIVERSAL NATURAL HISTORY 



the planets and the solution will then be immediately 

 applicable to them all. I reserve this solution for another 

 occasion, because it is necessarily connected with the prob- 

 lem which the Royal Academy of Sciences at Berlin have 

 proposed as the subject of their prize for the year I754- 1 

 The theory which goes to explain the origin of the 

 axial rotations, must also be able to derive the position 

 of their axes towards the plane of their orbits from the 

 same causes. We have reason to wonder why the equator 

 of the diurnal rotation is not in the same plane with that 

 of the orbits of the satellites which revolve around the 

 same planet; for the same movement which has directed 

 the revolution of a satellite, from its extending to the 

 body of the planet, ought to have produced its rotation 

 around its axis, and communicated to it the same de- 

 terminate direction and position. Heavenly bodies which 

 have no satellites revolving round them do, nevertheless, 

 put themselves into axial rotation by this same movement 

 of the particles which made up their matter, and by the 

 same law which restricted them to the plane of their 

 periodic path of revolution, which, for the same reasons, 

 must coincide in direction with the plane of their orbit. 

 In consequence of the action of these causes the axes of 

 all the heavenly bodies ought properly to be perpendicular 

 to the universal relative plane of the planetary system, 

 which does not deviate far from the ecliptic. But the 

 axes are only perpendicular in the two most important 

 members of this system, Jupiter 2 and the Sun. 



1 Kant discusses and solves this question in his remarkable tractate 

 (translated above) entitled : Examination of the Question whether the 

 Earth has undergone an alteration of its Axial Rotation. 1754. Tr. 



2 Jupiter has a small inclination of somewhat over 4 degrees. 



