SAMUEL PIERPONT LANGLEY. 4I 



1883. Results in Late Lunar Researches. Letter to Sidereal Messenger, 



Northfield, Minn., August, 1883, pp. 159-160. 



1884. A Vast Dust Envelope. Sidereal Messenger, Northiield, IMinn.. Febru- 



ary, 1884, pp. 21-23. 

 1884. Experimental Determination of Wave-lengths in the Invisible Prismatic 



Spectrum. American Journal of Science, New Haven, 1884, 3rd 



series, vol. 2"], pp. 169-188, pi. i, figs. 5. 

 1884. Experimental Determination of Wave-lengths in the Invisible Prismatic 



Spectrum. From the American Journal of Science, New Haven, 



1884. 3rd series, vol. 27, pp. 1-20, pi. i. 



1884. Annvial Report of the Director. Hand Book of the Observatory, Alle- 

 gheny, May 2"], 1884, pp. 39-41. 



1884. On the Change of Astronomical Day. Proceedings of the American 

 Metrological Society, New York, 1885, from May, 1884-December, 



1885, p. 70. 



1884. Experimental Determination of Wave-lengths in the Moisible Pris- 

 matic Spectrum. The London, Edinburgh, and Dublin Philosophical 

 Magazine and Journal of Science, London, 1884, 5th series, vol. 

 XVII, pp. 194-214, pis. VIII and ix. 



1884. Memoir on the Experimental Determination of Wave-lengths in the 

 Invisible Prismatic Spectrum. Memoirs of the National Academy of 

 Sciences, Washington, 1884, pp. 1-16, pis. 4. 



1884. Experimentelle Bestimmung der Wellenlangen im unsichtbaren prisma- 

 tischen Spectrum. Annalen der Physik un Chemie, Leipzig, Neue 

 Folge, Band xxii, pp. 598-612, pi. i, figs. 5. 



1884. Experimentelle Bestimmung der Wellenlangen im unsichtbaren prisma- 

 tischen Spectrum. Separat-Abdruck aus den Annalen der Physik und 

 Chemie, Leipzig, 1884, Neue Folge, Band 22, pp. 598-612, pi. i, figs. 5. 



1884. On the Amount of Atmospheric Absorption. American Journal of Sci- 

 ence, New Haven, September. 1884, vol. 28, pp. 163-180. 



1884. On the Amount of Atmospheric Absorption. From the American Jour- 

 nal of Science, New Haven, September, 1884, pp. 1-18. 



1884. Researches on Solar Heat and Its Absorption by the Earth's Atmos- 

 phere. A Report of the Mount Whitney Expedition. Professional 

 Papers of the Signal Service, No. xv, Washington, 1884, pp. 1-242, 

 pis. 24. 



1884. The New Astronomy. I. Spots on the Sun. Century Magazine, New 

 York, September, 1884, pp. 712-726, figs. 28. 



1884. The New Astronomy. II. The Sun's Surroundings. Century Magazine, 

 New York, October, 1884, pp. 922-936, figs. I9- 



1884. The New Astronomy. III. The Sun's Energj^ Century Magazine, New 



York, December, 1884, pp. 224-241, figs. 12. 



1885. The New Astronomy. IV. The Planets and the Moon. Century Maga- 



zine. New York, March. 1885, pp. 700-721, figs. 16. 

 1885. Sunlight and the Earth's Atmosphere. Weekly Evening Meeting of the 

 Royal Institution of Great Britain, London, April 17, 1885, pp. 1-18. 



pi. I. 

 1885. Sunlight and the Earth's Atmosphere. Nature, London. May 7, 1885. 



part I, pp. 17-20. 

 1885. Sunlight and the Earth's Atmosphere. II. Nature, London, May 14, 



1885, pp. 40-43, fig- I- 



