64 Dr J. W. Dawson on the Antiquity of Man. 



man was "many ten thousands of years" ago. Adopting 

 the biblical theory, so to speak, that a great subsidence, of 

 which modern history affords no example, has occurred 

 within the human period, we might adopt a very much 

 shorter chronology. It would seem at present that the 

 facts can be explained on either view, and that the possi- 

 bility of reconciling these views must depend on the greater 

 or less evidence which geologists may find of more rapid 

 changes than they have heretofore supposed within the 

 human period. Our own impression, derived from a careful 

 study of all the facts so well stated by Sir C. Lyell, is, that 

 the tendency will be in this direction, that the apparent 

 antiquity of the comparatively insignificant deposits con- 

 taining remains of man and his works will be reduced, and 

 that a more complete harmony than heretofore between the 

 earliest literary monuments of the human race and geo- 

 logical chronology will result. At present the whole in- 

 quiry is making rapid progress, and the time may perhaps 

 be not far distant when its difliculties will receive some 

 such solution. Tn the meantime, both of the writers 

 whose works are noticed in this article deserve careful 

 study, and will be found to contribute much toward the 

 solution of these great questions. 



The Observed Motions of the Companion of Sirius con- 

 sidered with Reference to the Disturbing Body indicated 

 by Theory. By T. H. Safford, Assistant at the Ob- 

 servatory of Harvard College. Communicated by the 

 Author.* 



It is well known to astronomers that the motions of the 

 bright star Sirius indicated the presence of a disturbing 

 body, before the discovery of a companion by Mr Alvan 

 Clark. It was shown by Bessel,t that there were irregu- 

 larities in the motion of this star in right ascension which 

 were only to be explained by the presence of an unseen 



* From the Proceedings of the American Academy of Arts and Sciences, 

 vol. vi. 



t Astrunomische Nachrichten, Nos. 514-516. 



