£". Spectrum of I Puppis. 

 h. Spectrum of ISIeteor as photographed. 

 ?'. Spectrum of ^Meteor, enlarged 9 times. 

 /. Variations in Light of U Pegasi. 

 k. Proper ^Motion of Z. C. 5I1 243 and occultation of 26 



Arietis. 

 /. Dumbbell Nebula. 

 1)1. Spiral and Ring Nebulse. 

 n. Nebula in Andromeda. 



2. Photographs of Apparatus and of Stellar Spectra, 



Illustrating a New ^Method. Exhibited by Prof. 

 Charles Lane Poor, of Johns Hopkins Observatory. 



a. Concave grating spectroscope; ordinary form attached 

 to eye end of telescope. 



b. Concave grating spectroscope ; direct form. 



c. Same as b^ mounted on telescope. 



d. Series of spectra of Sirius, including Glass positive, or- 

 dinary size ; photograph enlarged three times without 

 widening; photograph, enlarged and widened; Glass 

 positive, enlarged and widened ; Series of Spectra of 

 other stars. 



3. Charts axd Sketches. Exhibited by United States Coast 



and Geodetic Survey, H. S. Pritchett, Superintendent,. 

 Washington, D. C. 



a. Isogonic and Isoclinic Charts for 1900 A. D. 



b. Base map showing astronomical positions and gravity 

 stations to date. 



c. Sketch showing the Triangulation of the Great Transcon- 

 tinental arc from Cape May, New Jersey, to Point Arena, 

 California. 



4. Glass Positives. Exhibited by the Yerkes Observatory of 



the University of Chicago, George E. Hale, Director. 



a. Photographs of the Building and Instruments of the 

 Yerkes Observatory. Thirty positives on glass. 



b. Stellar spectra photographed with the 40-inch telescope 

 and stellar spectographs by Hale. 



