DRY-FARMING IN TUNIS AND AMERICA 353 



of an amphitheater large enough to accommodate 

 sixty thousand persons, and in an area of one hundred 

 square miles there were fifteen towns and forty-five 

 villages. The country, therefore, must have been 

 densely populated. In the seventh century, accord- 

 ing to the Roman records, there were two million 

 five hundred thousand acres of olive trees growing in 

 Tunis and cultivated without irrigation. That these 

 stupendous groves yielded well is indicated by the 

 statement that, under the Ca?sars, Tunis was taxed 

 three hundred thousand gallons of olive oil annually. 

 The production of oil was so great that from one 

 town it was piped to the nearest shipping port. 

 This historical fact is borne out by the present revival 

 of olive culture in Tunis, mentioned in Chapter XIL 

 Moreover, many of the primitive peoples of to-day, 

 the Chinese, Hindus, Mexicans, and the American In- 

 dians, are cultivating large areas of land by dry-farm 

 methods, often highly perfected, which have been 

 developed generations ago, and have been handed 

 down to the present day. Martin relates that the 

 Tarahumari Indians of northern Chihuahua, who are 

 among the most thriving aboriginal tribes of north- 

 ern Mexico, till the soil by dry-farm methods and 

 succeed in raising annually large cjuantities of corn 

 and other crops. A crop failure among them is 

 very uncommon. The early American explorers, 

 especially the Catholic fathers, found occasional 

 tribes in various parts of America cultivating the 



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