REPORT OF ASSISTANT SECRETARY. 55 



On Atmospheric Radiation of Heat in Meteorology. C. Abbe. 



On the Deflecting Forces that Product' the Diurnal Variation of the Normal Ter- 

 restrial Magnetic Field. F. H. Bigelow. 



Abstract of Results from the U. S. Coast and Geodetic Survey Magnetic Observa- 

 tory at Los Angeles, Cal., 1882-1889, Pari III. Differential Measures of the Hori- 

 zontal Component of the Magnetic Force. C. A. Schott. 



On the Anatomy and Systematic Position of the Mecoptera. A. S. Packard. 



On the Laws of the Variation of Latitude. S. C. Chandler. 



On the Causes of Variations of Period in the Variable Stars. S. ('. Chandler. 



On the Force of Gravity at Washington. T. C. Mendenhall. 



On the Recent Variations of Latitude at Washington. T. C. Mendenhall. 



On the Acoustic Properties of Aluminum, with experimental illustrations. A.M. 

 Mayer. 



Disruption of the Silver Haloid Molecule by Mechanical Force. M. Carey Lea. 



On the Homologies of the ( Iranial Arches of the Reptilia. E. D. Cope. 



On the Osteology of the genus Anniella. E. D. Cope. 



The Astronomical, Geodetic and Electrical Consequences of Tidal Strains within 

 an Elastic Terrestrial Spheroid. C. Abbe. 



Asiatic Influences in Europe. E. S. Morse. 



Exhibition of Chladni's Acoustic Figures transferred to paper without distor- 

 tion. A.M.Mayer. 



On Electrical Discharges through poor vacua, and on Coronoidal Discharges. 

 M. I. Pupin. 



Biographical Memoir of William Ferrel. C. Abbe. 



A definition of Institutions. J. W. Powell. 



Several other societies held their annual meeting in Washington. 

 Among them may be mentioned the National Art Association, May 10- 

 30; American Microscopical Society, August 11,12; Association of 

 American Agricultural Colleges and Experiment Stations, August 12- 

 15; Association of Official Agricultural Chemists. August 13,15; So- 

 ciety for the Promotion of Agricultural Sciences. August 1 7. 18; Wash- 

 ington Chemical Society, August 17, 18; Geological Society of America. 

 August 23,24; International Congress of Geologists, August 25-Sep- 

 tember 1; American Association for the Advancement of Science, Au- 

 gust 17-September 2. 



STUDENTS. 



During the past year, as heretofore, the National Museum has con- 

 tinued to aid students and others engaged in scientific work by lend- 

 ing them material to be used in connection with their researches. 

 Among the more important loans made during the year are the follow- 

 ing : A specimen of Maia to Mr. J. E. Ives, of the Philadelphia Academy 

 of Natural Sciences. Pieces of Gorgonians and sponges for micro- 

 scopic work to Mr. G. R. Lunisden, Greeneville, Conn. ( Jrayfisb.es, from 

 Lake Chapala, Mexico, to Prof. Walter Faxon, Museum of Comparative 

 Zoology, Cambridge, Mass. An example of Dendroica pityophila to 

 Mr. C. P>. Cory, Boston, Mass. Central American birds to Mr. Osbert 

 Salvin, London. England. Turtles to Dr. G. Baur, Clark University, 

 Worcester, Mass. Anatomical specimens to Prof. It. Wiedersheim. 

 Freiburg, Germany. Anatomical specimens to Mr. W. B. Barrows, 



