SCHIAPARELLl'S LATEST VIEWS REGARDING MARS. 119 



be an importaut factor iu its physical changes, but would give place 

 to carbonic acid, or to some other liquid whose freezing point was 

 much lower. 



The elements of the meteorology of Mars seem, then, to have a close 

 analogy to those of the earth. But there are not lacking, as might be 

 expected, causes of dissimilarity. From circumstances of the smallest 

 moment nature brings forth an infinite variety in its oj)erations. Of 

 the greatest influence must be different arrangement of the seas and 

 the continents upon Mars and upon the earth, regarding which a 

 glance at the map will say more than would be possible in many words. 

 We have already emphasized the fact of the extraordinary jjeriodical 

 flood, which at every revolution of Mars inundates the northern polar 

 region at the melting of the snow. Let us now add that this inun- 

 dation is spread out to a great distance by means of a network of 

 canals, i^erhaps constituting the principal mechanism (if not the only 

 one) by which water (and with it organic life) may be diffused over 

 the arid surface of the planet. Because on Mars it rains very rarely, 

 or perhaps even it does not rain at all. And this is the proof. 



Let us carry ourselves in imagination into celestial space, to a point 

 so distant from the earth that we may embrace it all at a single glance. 

 He would be greatly in error who had exx^ected to see reproduced there 

 upon a great scale the image of our continents with their gulfs and 

 islands and with the seas that surround them which are seen upon our 

 artiticial globes. Then without doubt the known forms or part of them 

 would be seen to appear under a vaporous veil, but a great part (per- 

 haps one-half) of the surface would be rendered invisible by the 

 immense fields of cloud, continually varying in density, in form, and 

 in extent. Such a hindrance, most frequent and continuous in the 

 polar regions, would still impede nearly half the time the view of the 

 tenij)erate zones, distributing itself in capricious and ever varying con- 

 figurations. The seas of the torrid zone would be seen to be arranged 

 in long parallel layers, corresj)Ouding to the zone of equatorial and 

 tropical calms. For an- observer placed upon the moon the study of 

 our geography would not be so simple an undertaking as one might at 

 first imagine. 



There is nothing of this sort in Mars. In every climate and under 

 every zone its atmosj)here is nearly perpetually clear and sufficiently 

 transparent to permit one to recognize at any moment whatever the 

 contours of the seas and continents and, more than that, even the minor 

 configurations. Not indeed that vapors of a certain degree of opacity 

 are lacking, but they offer very little impediment to the study of the 

 topograx^hy of the x^lauet. Here and there we see ai^x^ear from time to 

 time a few whitish spots, changing their x^osition and their form, rarely 

 extending over a very wide area. Tliey frequent by x>reference a few 

 regions, such as the islands of the Mare Australe, and on the conti- 

 nents the regions designated on the max) with the names of Elysium 



