TEE NITRATE FIELDS OF CHILE 211 



has been worked looks as though it had been badly furrowed by gigantic 

 ploughshares. In othe^ places, there is almost no overlying material to 

 remove. The layer of caliche may be as much as six feet thick, but for 

 the most part it varies between one and three feet. The beds in some 

 sections are fairly continuous over large areas; in others they are of 

 very limited extent. Some caliche contains more than 70 per cent, of 

 nitrate, but 50 to 60 per cent, is considered high ; the average is iiearer 

 20 to 30 per cent., and even as low as 15 per cent. is. worked profitably. 

 Hence the conditions of production, costs of operation and profits to be 

 made vary w^idely from place to place. With few exceptions, however, 

 it is true that the costs of operation are low as compared with many 

 other mining industries, while the profits are large. 



The main nitrate fields lie in two provinces, Tarapaca and Anto- 

 fagasta, between latitudes 19° S. and 27° S. Other deposits doubtless will 

 be found farther south in Atacama, and there are said to be small nitrate 

 areas in Tacna, the most northerly province of Chile. The total area of 

 these four provinces (105,000 square miles) is about equal to that of 

 Colorado and its population (316,000) gives about two per square mile. 

 Most of the people depend directly or indirectly on the nitrate industry. 

 Chileans are the most numerous, but there are also many Bolivians and 

 Peruvians, with smaller numbers of people from half the nations of the 

 world. Only small parts, probably much less than 10 per cent., of the 

 provinces named are workable nitrate lands. These limited areas, to- 

 gether with the seaport cities, contain the mass of the population, while 

 many thousands of square miles contain not a living soul nor any other 

 living thing. 



The nitrate beds lie in a belt, commonly less than ten miles wide, 

 about 500 miles long north and south, and 15 to 100 or more miles back 

 from the coast. This short distance from the coast is important in ma- 

 king shipment cheap. Along the coast there is a range of low moun- 

 tains through which a few ravines ofl^er routes for railroads into the in- 

 terior. Between the Coast Mountains and the base of the tow'ering 

 Andes lies lower land, known as the pampa, which slopes westward from 

 the Andes to the Coast Ranges. The nitrate deposits lie along the west- 

 ern side of the pampa, its lowest part, associated with what were once 

 the bottoms of water-filled basins, either lakes or arms of the sea. Lines 

 of flats, covered with dazzling white salt beds, or salares, extend over 

 many square miles. Thus one salt field in Tarapaca covers an area of 

 more than 100 square miles, and salt of remarkable purity (over 99 per 

 cent, pure) is said to extend to depths of scores of feet. Eound about 

 these salares are the nitrate lands or salitreras. In many parts of the 

 region there is a saying : " AYhere there is salt there is no caliche.'* 

 Though this saying holds true generalh', there are some places where 

 the two deposits occur together. The presence of nitrate, however, is 

 easily determined. In a manner much like that of using flint and steel 



