PHILOSOPHICAL SOCIETY OF WASHINGTON. 13 



ure was no doubt greater than usual, and j^et it was 50 per cent, 

 less than at St. Louis. 



When the sky was entirely free from clouds, the firmament was 

 indescribably brilliant — and so much more than at the sea level 

 that the value, to the unassisted eye, of the increased transparency 

 ■of the atmosphere was assumed at one, if not two magnitudes. 

 Stars of the fifth magnitude were observed for determination of 

 time before sunset with the telescope of the small portable 

 transit, and the companion to Polaris, ninth magnitude, was dis- 

 tinctly visible at night with a reconnoitring telescope of 2^ 

 inches aperture. The greater steadiness and definition were 

 very apparent during the observations made on sixty different 

 time stars. 



Prof. Young states in his report to the Superintendent of the 

 Coast Survey that hundreds of small stars wliich he had never 

 seen at Hanover, came out distinctly, and that he thought a 

 majority of the stars rated in the British Association Catalogue 

 of the seventh magnitude, were fairly within reach of the naked 

 eye. As an expression of the value of the elevation, he gives it 

 as his deliberate opinion that at Sherman the 9j-\ inch object 

 glass of the 12 foot equatorial was just about equal to a 12 inch 

 glass at the sea-level. The discoveries made by Prof. Young of 

 new lines in the spectrum of the chromosphere, and his observa- 

 tions on the spectra of solar spots and on solar storms, have been 

 published by him. 



While the reconnaissance adds another proof of the advantages 

 to be derived by so great an elevation of the telescope, the Me- 

 teorological Register clearly intimates that a more favorable 

 position than Sherman should be searched for, in view of any 

 proposition to erect a permanent observatory on the Rocky Moun- 

 tains to be devoted to the advancement of astronomical science 

 and discovery. 



A full report of the expedition, illustrated with tables and dia- 

 grams, will appear in the Annual Report of the Superintendent 

 of the Coast Survey for 1872. 



Mr. R. Keith read a paper 



ON ACHROMATIC OBJECT GLASSES. 



Mr. G. A. Otis made a communication 



ON FRACTURES OF THE INNER TABLE OF THE CRANIUM. 



Mr. T. Gill made some remarks 



ON THE HOMOLOGIES OF THE ARM IN FISHES, AND THE DEVELOP- 

 MENT OF THE HUMERUS IN GANOIDS. 



