ANNOUNCEMENT OF MEETINGS OF THE ACADEMY AND 



AFFILIATED SOCIETIES 1 



Wednesday, May 10: The Geological Society, at the Cosmos Club, at 

 8 p. m. Program: 



W. C. Alden: The Ioioan stage of glacialion; a review of the evidence, based on 

 field studies in 1914 and 1915 by the U. S. Geological Survey and the Iowa 

 Geological Survey. 25 minutes. Illustrated. 



F. C. Schrader: Ore deposits of the Rochester district, Nevada. 20 minutes. 



H. S. Washington: The Persistence of the volcanic vents at Stromboli, Italy. 

 15 minutes. Illustrated. 



Thursday, May 11: The Washington Society of Engineers. 



^Members of the Society and their friends, with ladies, will visit the plant of the 

 Newport News Ship Yard and Dry Dock Company, Newport News, Va., on 

 Friday, May 12. The party will leave on the regular Norfolk boat at 6.45 p. m., 

 Thursday, May 11, reaching Old Point Comfort Friday morning. Breakfast 

 will be served at Hotel Chamberlain, after which the party will go by trolley to 

 Newport News and visit the plant during the forenoon by invitation of the Com- 

 pany. After luncheon at Hotel Warwick in Newport News, the party will disband, 

 to return by the regular boat on Friday, Saturday, or Sunday night, as desired. 

 Orders for tickets should be in the hands of the Treasurer not later than May 4. 



Saturday, May 13 : The Philosophical Society, at the Cosmos Club, 

 at 8.15 p. m. Program: 



C. W. Hewlett (Johns Hopkins University) : An apparatus for the analysis of 

 sound waves. 



J. A. Anderson (Johns Hopkins University) : Diffraction gratings, their prepa- 

 ration and use. 



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1 The programs of the meetings of the affiliated societies will appear on this page if ssnt to the 

 editors by the first and fifteenth days of each month. 



