74 bulletin of the 



40th Meeting. February 1, 1873. 



The President in the Chair 

 Mr. Benj. Alvord read a paper 



ON THE HABITABILITY OF THE ELEVATED PLATEAUS OP THE WEST. 



Professor Benjamin Peirce, of Cambridge, made some remarks 



ON THE THEORIES OP THE NATURE OF COMETS' TAILS. 



(TVie substance of this commuvication had been preinously communicated to the 

 American Academy of Arts and Sciences, at Boston.') 



Mr. E. B. Elliott made a communication 



ON LIFE AND ANNUITY TABLES, BASED ON THE CENSUS OP 1870. 



41st Meeting. February 15, 1873. 



The President in the Chair. 

 Mr. M. Yarnall read a paper 



ON THE GENERAL STAR CATALOGUE PREPARED FROM THE OBSERTA- 

 TIONS AT THE NAVAL OBSERVATORY SINCE 1845. 



{The substance of these remarks is published in Washington Observations, 1871, 

 Appendix III.) 



Mr. W. Harkness made a communication 



ON THE POWER NECESSARY TO DRIVE THE PENDULUM OP AN 

 . ASTRONOMICAL CLOCK. 



42d Meeting. March 1, 1873. 



The President in the Chair. 

 Mr. E. FooTE read a paper 



ON THE LAWS OP CONDENSATION OP AQUEOUS VAPOR IN THE 

 ATMOSPHERE. 



Mr. C. E. Button presented a memoir 



on the causes of the elevations and the subsidences op the 

 earth's surface. 



