PORTION OF THE COSMOS. ZODIACAL LIGHT. 415 



knowledge, I have little to add to what I have already said 

 concerning it, derived from my own experience and from that 

 of others (Kosmos, Bd. i. S. 142149, and 409414, Aiim, 

 6178; Bd.iii. S. 88 : English edit YoLi. p. 127 133, 

 and xxxiii. xxxvii. Notes 91 99 ; Vol. iii. p. 228) . Twenty- 

 two years before the Zodiacal Light was seen and noticed by 

 Dominique Cassini, to whom its first observation is com- 

 monly ascribed, Childrey (Chaplain to Lord Henry Somerset), 

 in his Britannia Baconica, published in 1661, recommended 

 it to the attention of astronomers as a previously undescribed 

 phenomenon, which he had seen for several years in the 

 month of February and in the beginning of March. I think 

 it also right to remind my readers of a letter from Bothrnann 

 to Tycho Brahe (noticed by Gibers), from which it 'appears 

 that, as early as the end of the 16th century, Tycho had 

 seen and remarked the shining of the Zodiacal Light, and 

 had taken it for an abnormal vernal evening twilight. I was 

 myself first stimulated to make this phenomenon the object 

 of persevering observation, from being struck, as I was 

 quitting Europe, with its increasing brightness in Spain, on 

 the coast of Valencia, and in the plains of New Castille. I 

 found that the strength of the light, I might almost say of 

 the illumination, increased astonishingly as I approached the 

 equator in South America and in the Pacific. In the 

 ever-dry clear air of Cumana, in the grassy steppes (Llanos) 

 of Caracas, on the high table-lands of Quito and the 

 Mexican Lakes, and more particularly at elevations from 

 eight to twelve or thirteen thousand feet, where I was 

 able to remain for a longer time, I found its brightness 

 sometimes surpass that of the finest parts of the Milky Way, 



z 2 



