42 



DISCOVERY 



Mandeville, Jamaica. In 1894, maintaining that 

 " observatories should be erected where they may 

 see rather than be seen," Professor Percival Lowell, 

 of Boston, founded and equipped the Lowell 

 Observatory at Flagstaff, in Arizona. Here for the 

 period of twenty- two years, until his premature and 

 lamented death in 1916, Lowell untiringly scrutinised 

 the surface of Mars, following the planet for long periods 

 both before and after opposition. The work of Lowell, 

 Pickering, and the various observers who have assisted 



JI.\RS 1907, July S-13. (I,OWEI.L OBSERVATORY.) 



and collaborated with them has in great measure 

 revolutionised our knowledge of Mars. 



The observations of Schiaparelli himself had cast 

 doubt upon the aqueous character of the so-called 

 " seas " ; and W. H. Pickering's observations in 1892 

 still further weakened the conventional theory. In 

 1894 Lowell and his assistant, Douglass, announced that 

 the canal-system was not confined to the reddish-ochre 

 or continental areas, but was planet-wide, the canals 

 traversing the so-called oceans as well as the continents. 

 It became obvious, therefore, that there are no per- 

 manent bodies of water on the Martian surface, the so- 



called seas are simply low-lving tracts of vegetation, and 

 that the only " seas " on our neighbour world are 

 temporary — the polar seas which result from the 

 melting of the ice-caps in the spring and summer, and 

 the temporary floods which overspread low-lying areas 

 from time to time. 



Of special significance was Pickering's detection, in 

 1892, of round spots at the junctions of the canals, the 

 existence of which Schiaparelli had suspected, but had 

 never been able to place beyond doubt. These were 

 called " lakes " by their discoverer, in keeping with the 

 older views of the planet's physical condition. This 

 discovery was confirmed by Lowell, who detected 

 considerable numbers of these spots ; he designated 

 them as " oases," in keeping with the newer view. 

 For Lowell demonstrated beyond doubt that the 

 continental areas are desert lands — " not only land, but 

 nothing but land — land very pure and simple ; that is, 

 deserts." The dark lines designated as canals and the 

 dark spots at their junctions were shown to be vegetal 

 in their nature, as Schiaparelli suggested soon after 

 their discovery. For the canal-system is obviously 

 dependent upon the polar cap. As the cap melts 

 the canals darken, and a wave of verdure sweeps from 

 pole to equator and into the opposite hemisphere. 

 Obviously the melting of the snow-fields, on a world 

 where water is scarce and where the air is clear and 

 dry, is the controlling factor in the planet's physical 

 life. In some manner the narrow strips of vegetation 

 which we call canals are fertilised by water from the 

 polar seas, which are formed from the melting snows. 



Here certainty ends, and we must be content with 

 hypotheses more or less plausible . The most thorough- 

 going and elaborate theory is that which Lowell 

 enunciated in his first book on Mars in 1895, and 

 developed in his later volumes — a theory which is 

 familiar even to the casual reader of scientific literature. 

 In his view, the canal-system can only have come into 

 existence as the result of intelligent agency. Mars is 

 relatively a much older world than ours, in the later 

 stages of planetary existence. Water is scarce, and if 

 there are inhabitants there, they must be fighting a 

 grim battle against the spectre of death by thirst. 

 The geometrical regularity of the canal-system, 

 and the rate of development of the individual canals 

 — indicating a transference of water " in the face 

 of gravity " — were held by Lowell to point to the 

 existence of intelligent life on the planet, at least 

 within the areas which he termed " oases," and which 

 he believed to be centres of population or " city-states." 



Various alternative theories have been put forward, 

 and from time to time Professor Pickering has outlined 

 possible explanations of the canals. In 1915 he 

 suggested that the water necessary for the growth of 

 vegetation in the strips known as canals might be 



