120 THE PLANET MARS: IS IT INHABITED? 



Mr. Lowell draws attention to three remarkable characteristics 

 of these lines : i. — Their unnatural straightness, so diiferent from 

 anything of the kind observable upon Earth. Almost invariably 

 they are arcs of great circles. 2. — Each line appears the same 

 uniform width throughout. 3. — No line is absolutely isolated, 

 which means that, starting from any point on any line, the whole 

 network of lines might be successively traversed. In regard to 

 these characteristics, it may be observed that angularity or devia- 

 tions from straightness, also intervals or interruptions in the canal 

 system, even to the extent of fifteen miles or more in each case, 

 would not be perceptible from Earth in the best of telescopes. 

 Such deviations, rendered necessary to round hills here and there, 

 are indeed to be expected j but nothing conceivable in the canal 

 system would necessitate absolute discontinuations. Stretches of 

 sandy desert might indeed occur here and there, useless for irriga- 

 tion purposes, but through which the water could easily be 

 conducted without loss. 



Perhaps the most inexplicable phenomenon upon Mars is the 

 gradual widening, then doubling, or splitting in two, of what at 

 first appeared as a single ordinary canal. Mr. Lowell's map shows 

 seven of these double canals, the distance between the lines in 

 each case measuring from one hundred and twenty to one hun- 

 dred and seventy-five miles, the intermediate country being of an 

 orange-ochre tint. From the fact that other lines appeared on 

 the point of doubling, and others, again, very broad, it may turn 

 out that doubling is rather the rule than the exception. Mr. Lowell 

 believed the doubling (one or two cases of tripling have been 

 recorded) to be seasonal and vegetal. The theory is plausible, 

 though unsatisfactory, he thinks, which sees in the slow divergence 

 of the lines a progressive growth and decay, as the lines of vege- 

 tation recede from each other. In every case, he says, the lines 

 appear straight and exactly parallel ; and the better they are seen 

 the straighter they appear. The solution of this strange doubling 

 cannot fail to be significant and intensely interesting when it comes. 



One of the most telling points in Mr. Lowell's contention that 

 the dark areas are not water, is the discovery that dark lines 

 and dark spots are not confined to the light reddish or sandy- 

 coloured regions, but prevail also in the dark regions ; in fact, the 



