OF ARTS AND SCIENCES. 



333 



derived from Mr. Bond's observations is far more satisftictory tiian that 

 which ]\I. Stnive has obtained from his own observations. 



" The fifth and sixth columns of the table contain the small discrepan- 

 cies between theory and observation which would have remained after 

 making allowance for the action of the hypothetical planets of Adams 

 and Leverrier ; and their comparison with the second column shows 

 that the observation of 1690 was not sulRciently well represented by 

 the theories which resulted in the discovery of Neptune. 



" The seventh column contains the residual defects of the best theo- 

 ry of Uranus, which is independent of the action of an external plan- 

 et, and is the true basis of the researches of Adams and Leverrier. 

 This theory was constructed by Leverrier from all the modern observa- 

 tions, and the discrepancy between theory and observation was the final 

 proof that Uranus was subjected to some unknown cause of perturbation. 

 The time t is the number of Julian years from Jan. 1, 1850. The 

 longitude of the perihelion is denoted by zjt, with the symbol of the 

 planet subjacent. 



" Residual Differences between the Theoretical and Observed Longi- 

 tudes of Uranus, from the Theories of Peirce, Leverrier, and 

 Adams. 



