Glacial Xofes from the Planet JIars. — ('lat//>o/e. 93 
The recent opposition of Mars lias been industriously util- 
ized by various astronomers in securing observations under 
very favorable circumstances. As may be seen from our fig- 
ure, Mars and the earth can seldom be better placed for this 
purpose than they were during the summer and autumn of 
1894. Mars being in perihelion and the earth at mean dis- 
tance, the two globes were coursing along through space side 
"by side with an interval of less than 50 million miles b?tween 
them. Moreover, the illumination of Mars was at a maximum, 
the bright side being directed toward the night side of the 
earth so that he was visible from sunset to sunrise for several 
months. 
This admirable opportunity of scrutinizing the surface of 
our neighbor planet led to the confirmation of some previ- 
ous opinions and the discovery of not a few details. From va- 
rious sources the following account of our present knowledge 
and belief, as based on the researches of past and present as- 
tronomers, has been compiled. 
As already mentioned, the polar snows annually melt and 
diminish, and during the recent Martian summer the southern 
snow-cap entirely disappeared evidencing an unusually hot 
season. During its diminution there was seen bordering it a 
dark band of unequal breadth, but averaging in June, 1894, 
about two hundred miles. "It was the darkest marking on 
the disc and was blue.''' (Lowell.) 
The snow-cap extended down to 67^^ south latitude so that 
the dark boundary band was at least 6" in width and its 
northern end lay in south latitude (514^^. Of it Mr. Lowell of 
the Flagstalf Observatory in Arizona says: "The formation 
was water beyond a doubt, for it was of the color of water, it 
faithfully followed the melting of the snow, and it subsequent- 
ly vanished — three independent facts mutually cdulirmatory 
f)f this conclusion." 
Following the ap])carance of the waler band, says Mr. Low- 
ell, the well known system of Martian canals shares in tiie 
deepening of the color l)ut iem])orarily and in south-north 
succession. The so-called seas througli which tlie canals ])ass 
share also in the change of tint, (iradnally this dai'k hue 
spreads toward tiie planet's equator. (Jne after anothei- tiie 
markings on the surface become blue-green and in similar or- 
