64 RECENT CHANGES IN THE SURFACE OF JUPITER. 
Sir William Herschel, in 1793, wrote :—“TI suppose that the 
bright belts of Jupiter included between the faint belts are zones 
wherein the ie of the planet is oo densely filled with 
clouds. The faint belts correspond to the regions in w. 
atmosphere is perfectly serene, and allows rs solar rays to reach 
the solid portions of ok planet, via according to my opinion the 
reflection is less. powerful than clouds,” 
Mr. Proctor, who ea made a poy 5) study of the conditions 
under which J upiter exists, thinks that since Jupiter, owing to 
his great distance from the sun, only receives ¢'5 part of the light 
and heat which reach the earth, it is ap that his atmosphere 
should be loaded with clouds as we see it, resulting from sun heat 
alone, and that it is therefore extremely pfobabilé that the giant 
ually enormous masses of clouds to be ga ar 
under the influence of the swift rotation of the giant 
Not otherwise, Mr. Proctor thinks, can one understand whence his 
atmosphere is loaded with vapour masses. ; 
The observed facts which I have to bring before 1 oe 
distance and the many difficulties which the terrestrial 
the detasla upon the surface of Jupiter, owing to his enorme yous 
po piter, § 5 hi re 
trained obser’ 
puts in our way. It is only the most patient and 
ing, aided by powerful telescopes, that enables us to detect - 
minute markings on the planet which are all-important in 
discussion before us. ofa 
There are markings, and even changes, which the possessor 
small telescope may see; but, to study Ju iter to 
r y u y 3 bia jee S 
result of my own observation has convinced me that fen 
think what follows will show that I have some groWl® 
thinking so ai 
Fi ne with regard to the permanence of the belts. Ibn i 
test this point by a careful any : 
a very fie micrometer. At that time the oquston wed 
four red-brown belts, which could be traced 
them was a fainter red colour, sufficient 
as one broad marking on the equator ; this was by n° or colot 
form ; in places the belts were interrupted by white 
