ASTRONOMICAL DOCTRINES, &o. 



Modern astronomers seem all to be agreed in opinion that 

 the moon rotates, or turns round on her axis, during the period 

 of her revolution about the earth. They speak of it as an indu- 

 bitable fact; and, without taking the trouble to examine it, I 

 was induced by their unanimity of opinion, and the authority of 

 their great names, to acquiesce in it as a matter of faith, though 

 inclined to be very sceptical about its truth. Some time ago, 

 however, my attention was accidentally called to this subject, 

 my doubts of its truth became stronger than ever, and I re- 

 solved to probe the matter to the bottom. The result is a 

 decided conviction that my faith has been misplaced, and that 

 the moon does not rotate, or turn round on her axis, in the 

 manner alleged. The investigation led me even further than 

 I anticipated ; for it suggested a consideration of the established 

 doctrine concerning the sidereal day, and the result of my inquiry 

 into that subject also is the same. The problems are so simple 

 that very few words might suffice to show how they are to be 

 solved ; but the received opinions have prevailed so long, and 

 have become so deeply engrained in the minds and systems of as- 

 tronomers, that it is necessary to examine in detail their argu- 

 ments and illustrations, in order to show fully and distinctly the 

 nature, the cause, and the absurdity of their errors. 



Professor Nichol of Glasgow, in his treatise on '* The pheno- 

 mena and order of the Solar Si/stem," says, ** The moon has one 

 very singular feature, apparently belonging essentially to her as 

 a satellite, since it distinguishes every other satellite with which 

 we are sufficiently acquainted. She rotates on her axis in the 

 same time in ivhich she revolves in her orbit round tlie earth, — in 

 other words, the length of one day and night in that orb is pre- 

 cisely one of our months. The rotations of Jupiter's satellites 

 also nicely correspond with the periods of tlieir revolution around 



