Vi CONTENTS. 



PAGE 



X. ■ 0)1 the Phosphorograph of a Solar Spectrum, and on the 

 Lines in its Infra-red Region. By John William 

 Draper, M.D 223 



XL On the Diiodbromacrylic and Chlorbromacrylic Acids. By C. 



F. JVIabery and Eachel Lloyd 235 



XIL Researches on the Substituted Benzyl Compounds. By C. 



LoRiNG Jackson 241 



XLLL Variable Stars of Short Period. By Edward C. Pick- 

 ering 257 



XIV. XIV. — Experiments on the Strength and Stiffness of Small 



Spruce Beams. By F. E. Kidder 285 



XV. Anticipation of the Lissajous Curves. By Joseph Lover- 



ING 292 



XVL Observations on Jupiter. By L. Troctvelot .... 299 



XVn. A Papier on the Propagation of Magnetic Waves in Soft 



Iron. By Harold Whiting 322 



XVIII. The Bolometer and Radiant Energy. By Prof. S. P. 



Langley 342 



XIX. On the Use of the Electric Telegraph During Total Solar 



Eclipses. By D. P. Todd, M.A 359 



XX. Large Telescopes. By Edward C. Pickering . . . 364 



XXI. Photometric Measurements of the Variable Stars /3 Persei 

 and DM. 81°25, made at the Harvard College Observatory, 

 By Edward C. Pickering, Director, Arthur Searle 

 and O. C. Wendell, Assistants 370 



XXII. On the Group "b" in the Solar Spectrum. By William 



C. WiNLOCK 398 



Proceedings 407 



Memoirs : — 



George B. Emerson 427 



John Chipman Gray 429 



