96 FROM NEBULA TO NEBULA 



This studious regard for choosing* the shortest distance, 

 according to Mr. Lowell, implies not only provident 

 economy in design but also a very high degree of tech- 

 nical knowledge and skill. Necessarily there are many 

 points of intersection, and, strange to say, at the major- 

 ity of these, he points out, there are circular dots about 

 75 miles in diameter, which in color correspond with 

 the canals. These Mr. Lowell conceives to be oases, 

 Martian cities, as it were, environed by irrigated farms. 

 Not this alone, these canals connect with certain caret- 

 shaped spots that appear to be the " salient points" of 

 the blue-green patches; and from certain of the oases 

 canals branch out numerously, always in straight lines, 

 to other oases, forming a sort of open network. They 

 always lead to definite destinations, never stop short as 

 rivers might do, and, again unlike rivers, they preserve 

 a surprising uniformity of line throughout. 



In the first days of summer of each hemisphere, 

 these canals, he states, begin to grow in distinctness, 

 starting at the polar cap soon after it commences to 

 thaw and thence gradually continuing down to the equa- 

 tor. At such times too certain of the canals have a 

 trick of pairing or doubling, technically known as "gem- 

 ination". 



The aggregate length of the canals is stupendous, 

 probably as much as 40,000 miles, or three times the 

 circumference of the Martian globe. Five hundred and 

 twenty-two of them have been mapped, the shortest be- 

 ing not less than 250 miles in length and the longest, 

 the Eumenides-Orcus, stretching the enormous distance 

 of 3450 miles. At least a dozen extend to points far 

 within the polar circles, and would no doubt be found 

 to reach even to the pole itself, were their ends not ob- 

 scured by the sharp retreating figure of the globe in that 

 high latitude. 



