92 REPORT OF THE SECRETARY. 



the volume was sent to the Public Printer in February, 1905, and bad been put 

 into type before the closing of the fiscal year. The contents of the Smithsonian 

 Report for 1904 is as follo^YS : 



159G. Journal of Proceedings of the Board of Regents of the Smithsonian 

 Institution at Meetings of December 8, 1903. and January 27 and March 7, 

 1904. Report of Executive Committee. Acts and Resolutions of Congress. 

 Pages XV-I.XXIX. 



1547. Report of S. P. Langley, Secretary of the Smithsonian Institution, for 

 the year ending June 30. 1904. Pages 1-108. plates i-xiv. 



1597. Experiments with the Langley Aerodrome. By S. P. Langley. Pages 

 113-125, plate i. 



1598. The Relation of Wing Surface to Weight. By R. Von Lendenfeld. 

 Pages 127-130. 



1599. The Rumford Spectroheliograph of the Yerkes Observatory. By 

 George E. Hale and Ferdinand EUerman. Pages 131-161, plates i-xvii. 



1600. Construction of Large Telescope Lenses. By Dr. C. Faulhaber. Pages 

 163-170. 



1601. Some Reflections suggested by the Application of Photography to 

 A.stronomical Research. By H. H. Turner. Pages 171-184. 



1602. Radiation in the Solar System. By Prof. J. H. Poynting. Pages 

 185-193. 



1603. Condensation Nuclei. By C. T. R. Wilson. Pages 195-206, plates 



t-VIII. 



1604. Present Problems of Inorganic Chemistry. By Sir William Ramsay. 

 Pages 207-220. 



1605. The Evolution of the Scientific Investigator. By Simon Newcomb. 

 Pages 221-233. 



1606. Metals in the Atmosphere. By Alfred Ditte. Pages 235-247. 



1607. Observations on Vision in Brightness and in Obscurity, with a Hypoth- 

 esis on the Cause of Color Blindness. By O. Lummer. Pages 249-258. 



1608. A Lightning Spiral Observed Near Basel. By Fr. Klingelfuss. Pages 

 259-260, plates i-ii. 



1609. Variations of Specific Gravity. By G. W. A. Kahlbaum. Pages 261- 

 266. 



1610. Some new Methods of Lighting. By A. Berthier. Pages 267-274, 

 plate I. 



1611. Progress in Wireless Telegraphy. By William Maver, jr. Pages 275- 

 280. • 



1612. Electric Welding Development. By Elihu Thomson. Pages 281-285, 

 plates i-v. 



1613. History of Discoveries of Photography. By Robert Hunt. (Revised 

 by T. VV^. Smillie.) Pages 287-308, plates i-vii. 



1614. Theories of Ore Deposition Historically Considered. By S. F. Emmons. 

 Pages 309-336. 



1615. On Mountains and Mankind. By Douglas W. Freshfield. Pages 337- 

 354. 



1616. Morocco. By Theobald Fischer. Pages 355-372. 



1617. The Work of the Reclamation Service. By F. H. Newell. Pages 373- 

 881. plates i-viii. 



1618. The Yuma Reclamation Project. By J. B. Lippincott. Pages 883-388, 

 plate I. 



1619. The Evidence of Evolution. By Hugo De Vries. Pages 389-396. 



1620. The Evolutionary Significance of Species. By O. F. Cook. Pages 

 397-412. 



