Marvels of the Universe 



6i 



for an hour or two in' each, daj- abnost to 

 the same height as in simOar regions here. 

 And as on Mars, o\ving to the low pressure 

 of the atmosphere, water will boil between 

 100° and 125°, instead of at 212^ as with 

 us, there need be no surprise that the thin 

 films of hoar frost are not only melted, but 

 probably evaporated as well. 



This view of the condition of the planet 

 is strengthened by an observation that has 

 frequently been made. In a beautiful draw- 

 ing made by M. Antoniadi with the great 

 thirty-three-inch telescope of the iMeudon 

 Obser\'atory on September 20, 1909, when 

 the southern hemisphere of the planet was at 

 its summer solstice, the bright region in the 

 lower part of the planet represents a ruddy 

 district, called by Schiaparelli, "Aeria." It 

 borders a dark marking having the form of 

 a cornucopia, the darkest marking on the 

 planet, and formerly known as the " Hour- 

 Glass Sea," but now as the " Syrtis Major." 

 It is a feature of Aeria and of several other 

 of the ruddy lands of Mars that when near 

 the edge of the disc — that is to say, early in 

 the morning of the region or late in its after- 

 noon — it becomes white instead of red, 

 pointing to a deposition of frost in some 

 form which disappears under the noonday 

 sun and forms again shortly before he sets. 

 In this case there can be no question of 

 anything more than a thin film, whether of 

 snow or of hoar frost, and as such regions 

 sometimes go far to rival the polar cap in 

 brightness, it is probable that it does not 

 materially differ from them in character. 



Under such conditions plant-life must 

 find it difficult to maintain the struggle for 

 •existence, even in its lowest and hardiest 

 forms. But for life in any of its highest 

 forms, we may dismiss Mars as quite un- 

 suited. For this a more genial chmate, a 

 denser and moister atmosphere, a less violent 

 range of daily temperature are required, 

 and these imply the conditions of a larger, 

 -denser planet, placed nearer to the sun ; 

 the conditions of our earth, mantled with 

 vegetation and veiled in vapour, richly 

 lowered with the cloud and with the leaf. 



CLOUD-FORMS IN MARS. 

 These forms were observed and drawn by a German astronomer, 

 Schrbter. who noticed the changes of their mass more particularly 

 round the equator. He therefore considered them to be clouds, and 

 if this be so it demonstrates the existence of atmosphere and there- 

 fore a possibility of life on the planet. 



