90 



E. WALTER MAUXr-ZR. F.E.A.S.. OX THE 



favourablv presented for our inspection. We see that part of 

 Mars which is at its best. 



But, as we have seen, the habitabilitr of a world turns upon 

 the presence and abundance of the compound water in the 

 liquid state. Here water melts at 32 degrees and boils at 

 212 degrees : thiough a range of 180 degrees it is in the liquid 

 state. And the mean temperature of our planet, and ot all 

 latitudes outside the polar circle, is above the freezing point 

 and far below the boiling point. Water with us, therefore, is 

 normally a liquid. On Mars the boiling point can only be 

 about 8U degrees alx;»ve freezing point, so that the range within 

 which water can exist as a liquid is very small. But tlie me^in 

 temperature of the planet as a whole, and of every latitude in 

 ]:»articular, is much l^elow the freezing point : the normal con- 

 dition of water there is that of ice. and it is impossible for it 

 to fulhl its great function of enabling organic life to receive 

 nutriment. The noonday tempera tme may indeed rise high 

 above the freezing point : may even reach the boiling point ; 

 init this can only suffice to melt a thin film of the surface ice. 

 As Professor Xewcomb puts it : " The most careful calculation 

 shows that if there are any considerable bodies of water on our 

 neighloming planet they exist in the form of ice, and can 

 never be liquid to a depth of more than one or two inches, and 

 that only within the torrid zone, and during a few hours each 

 day." 



Since the atmosphere is so thin and so little water is at any 

 time above the freezing point, there can at no time l»e any 

 great depositions of snow or rain. The polar caps, therefore, 

 cannot Ije vast accumulations of snow, but at the l»est a thin 

 deposit of hoar frost. The winters on Mars are seasons of what 

 we should call ' black frost '* : intense cold with but a very slight 

 jirecipitation of water vafKJur. 



It is doubtful, therefore, if there can be organic Life of any 

 kind : certainly, no life so highly organized as to deserve the 

 title of " inhabitanL" But it is conceivable that there i^ay he 

 some low form of plant, or perhaps even of animal life, capa-de 

 of coming into activity, maturing and reproducing itself within 

 the warmer hours of a Martian day, and of passing the night m 

 the form of spores. During the iron nights of Mars, even in 

 the tropics, it is not possible to conceive of life existing except 

 in embryo. 



And since there is no water to flow, there can be no water- 

 courses, natural or artificial. How is it then that Mr. Lowell 

 and his supporters see and draw this network of lines that looks 



