358 THi; POPULAR SCIENCE MONTHLY. 



" We find in the above table a strong argument for such a ring around the 

 earth. The figures, taking either of the two columns, for water or for glass, 

 correspond in a very striking degree with the varying intensity of the zodiacal 

 light from the base upwai'd, as we have it on any clear morning or evening when 

 the ecliptic is at a high angle with the horizon, and when, consequently, the 

 nebulous figure is not brought angularly to our eye. They also correspond to 

 what is, indeed, almost synonymous with what has been stated namely, to the 

 fact that at 4" 30" the zodiacal light at the horizon is far greater at its base than 

 it is at 3" 30" ; at 3" 30"" than it is at 2" 30", etc., back to midnight. Any person 

 who has ever looked attentively at tbis light when making a high angle with the 

 horizon will see at once the coincidence between the proportions of the figures 

 in the above table, showing the number of reflected rays, and what has been 

 always presented to the eye. If the reader will also carry these lines of incident 

 and reflected light beyond the midnight horizou-line, to any point there of the 

 nebulous ring, he will see how we may easily get what is referred to in my 

 charts under the German name of Gegensdtein, i. e., dim light seen, when the 

 circumstances are favorable for it, in those portions of the sky opposed to the 

 sun. This hypothesis shows also very clearly how I could have the zodiacal 

 light above both horizons at the midnight hours, as I was often able to do, and 

 it harmonizes fully with the strength of the light as then presented to the eye. 

 While there are some things still left unexplained, I have yet not been able to 

 see anything in this hypothesis antagonistic to the facts of the zodiacal light. 

 On the contrary, almost all of them are explained by it; and they all, as I can 

 perceive, fully harmonize with it through the whole of the manifold change 

 which the light underwent, either from the changes of the ecliptic toward any 

 fixed point, or from my numerous and great changes of latitude during our 

 cruise. 



" If we could have a zodiacal light of an undoubted character produced by 

 t\iQfull moon, not only would the question before us be set at rest, but the ring 

 would be shown to be within the orbit of the moon, and how near we came to 

 a case of the kind on the evening of February 14, 1854, the reader will decide 

 for himself. . . . 



" This ring must, according to the laws of matter, rotate on its centre ; and 

 it must be full of commotion within itself. The existence of j)uIsations seems 

 scarcely to admit of a doubt, recorded as they have been by observers in such 

 distant quarters of the globe." 



In conclusion, we would say that two simultaneous observations, 

 made in equatorial regions for instance, one by an observer at Quito, 

 and another by an observer on the island of Sumatra, iu which both 

 observations presented the zodiacal light stretching as an arch across 

 the heavens from east to west would, it seems to us, demonstrate 

 the fact that it is a ring around the earth. Now, if observations taken 

 in almost every space of 15 of longitude have been made and its 

 existence demonstrated, does not that amount to about the same 

 thing ? 



We leave the subject, inviting information and discussion from all 

 who are informed in regard to this long-neglected phenomenon. 



