254 POPULAR SCIENCE MONTHLY 



the most vulnerable feature is the instability of the foundation along 

 much of the levee line. 



The efficiency of the levee system is the test of all the labor and the 

 justification of the large expenditures. The increasing efficiency may 

 be measured in many ways. A comparison of the number of crevasses 

 and the total number of miles of destroyed levees with the records of 

 previous floods is the one in general use. In 1882, 284 crevasses were 

 recorded and 59 miles of levee were destroyed. This record has been 

 gradually improved. In 1890, but 23 crevasses were reported and 4.25 

 miles of levee destroyed. In 1897, the number of crevasses increased 

 to 49, with a loss of 8.3 miles of levee. In the 1903 flood, 9 crevasses 

 of importance were recorded and 5 of these caused a loss of 2.1 miles 

 of the levees. The loss of levees by caving banks was a little less than 

 1 per cent, of the entire contents. Last year (1904) in a period of 

 quieter flood the percentage was over 2.5. The number of square 

 miles of overflowed area in 1903 was .5 the mileage for 1897. There 

 is no doubt but that the levee system as it approaches completion is 

 being made stronger and safer. Yet each crevasse or natural break 

 spreading the confined waters over larger areas releases the tension 

 on the banks and to some extent prevents others from occurring. To 

 enclose the water which has spread naturally over 29,700 square miles 

 between two walls less than 5 miles apart and covering about one tenth 

 of its former area is no easy task. Till the present system is com- 

 pleted, the possibility of a flood will be uncertain that always grave 

 dangers may be incurred to life and property within the limits of the 

 alluvial basin of the river. 



The commissioners in their general report furnish the best proof 

 of the increased confidence in the levees by citing the progress and 

 growth of the Yazoo Basin since their board was created. The popu- 

 lation of this district was 94,672 in 1880, and 195,346 in 1900. The 

 present valuation of the basin is $42,000,000. The number of banks 

 have increased from 2 in 1893 to 51 ; the mileage of railroads from 225 

 in 1884 to 816. The cotton production in 1879 was 185,868 bales; 

 in 1903, 426,414. The increase in corn, peas, clover and alfalfa is 

 reported to be even greater than that of cotton. The original timber 

 of the basin is being cleared, and there are now large shipments of 

 lumber, as logs, boards, staves, headings and the like. Flourishing 

 crops are seen to-day where in former years the floods measured from 

 20 to 25 feet in depth. ' The Yazoo Basin is sprinkled with towns 

 whose sites were the home of the bear and the wild cat ten years ago.' 



The engineers of this district in their reports of the flood of 1903 

 state that about one fourth of the Yazoo Basin was under water during 

 this flood. Two crevasses occurred, letting water into the basin. One 

 of these, three miles below Greenville, Mississippi, was at its greatest 

 width a breach of 3,900 feet. The water flowed back upon Green- 



