THE 



AMERICAN 



JOURNAL OF SCIENCE AND AETS 



[SECOND SJERIES.] 



Art, XXXI. 



Observations on the Zodiacal Light; with an 



tnqinry into its Nature and Cofistituiion^ and its Relations to 

 the Solar System ; by Denison Olmsted, Professor of Natural 

 Philosophy and Astronomy, in Yale College, 



Kead before the American Association for the Advancement of Science, at the 



Annual Meeting at Albany, August, 1851. 



I SUBMIT to the Association a series of observations on the Zo- 

 diacal Light, made by me at Yale College from 1833 to 1839, 

 Ijpon the basis of which I propose to offer a new description of 

 this mysterious phenomenon, and a brief inquiry into its nature 

 ^nd constitution, and its relations to the solar system. Particu- 

 larly, I propose to inquire whether or not it is the origin of the 

 meteoric showers of November and August. 



* arious circumstances conspire to interrupt the continuity of a 

 series of observations on the zodiacal light; among which are 

 the following : 



1- The comparatively few nights in the year when, in our cli- 

 J>^ate, the sky is cloudless, and "the atmosphere sufficiently clear 

 to afford good observations on a light so feeble and diffuse. 



^; The low angle which the zodiacal light makes with the 

 norizon for the greater part of the year while it is visible. 



•5. The presence of the moon, which entirely effaces it ; and, 

 occasionally, for long periods, the presence of Venus or Jupiter, 

 and sometimes of both planets. The light of Venus, especially, 

 Js often so bright, and the planet is so situated in the midst of the 

 zodiacal light, as greatly to interfere with observations. Hence, a 



Seco.n-d Series, VqL XII, No. 36.-Xot., 1S51. 40 



