AGRICULTURAL ENGINEERING. 403 



the same material, and the whole process should be repeated after 6 or 8 days. 

 Poultry raisers are advised to give a little extra feed at molting time in order to 

 hasten the growth of the new feathers. 



Insects as carriers and spreaders of disease, L. O. Howard ( U. S. Dept. Agr. 

 Yt'orbool- 1901, pp. 177-19J, Jigs. 16) . — A brief account js given of the agency of mos- 

 quitoes, flies, and other insects and related animals in transmitting malaria, typhoid 

 fever, yellow fever, and other diseases. Attention is called to the ditticulties met 

 with in combating these diseases in country localities where the breeding places for 

 flies and mosquitoes are especially favorable. Notes are given on the best measures 

 to be adopted in destroying flies and mos(iuitoes in various stages, and thus prevent- 

 ing any opportunity of spreading malaria and typhoid. 



Insects as factors in the transmission of disease, H. Skinner {Pennsylvania- 

 Dept. Agr. Rpt. 1901, pt. l,pp. 329-333). — This paper contains a brief popular account 

 of the agency of insects, particularly mosquitoes and flies, in the transmission of 

 malaria, yellow fever, and typhoid fever. 



AGRICULTURAL ENGINEERING. 



Utilizing our water supply, A. J. McClatchie {Arizona Sta. Bui. 43, pp. 59-141, 

 figs. 9). — This is a discussion of the best means of utilizing the water supply of Ari- 

 zona, especially that of the Salt River Valley, based largely on investigations at the 

 station (E. S. E., 14, p. 195) on "the amount of water needed by various crops, the 

 returns per acre of land and per acre-foot of water, from the application of a given 

 amount of water, and the best methods of irrigating various crops." The sources, 

 fluctuation, and total and available amounts of the water supply; api:)ropriation, dis- 

 tribution, and duty of the water sui^i^ly; and means of increasing the available amount 

 and duty of the supply, are discussed. 



The watershed of the Salt River covers an area of 12,000 square miles. Its topog- 

 raphy and climate are such as to cause great variations in the flow of the streams 

 that drain it, but the average flow of Salt River below the mouth of its largest tribu- 

 tary, the Verde, has been ajiproximately 1,200,000 acre-feet per year during the 

 past 41 years. There are 275,000 acres of land under canal in Salt River Valley. 

 This is more than the total water supply will irrigate. The amount of water actually- 

 used for irrigation is less than one-half of the total supply. It is estimated that the 

 water supply at present available would properly irrigate 110,000 acres, which might 

 be safely increased to 160,000 or 180,000 acres by the construction of the proposed 

 Tonto reservoir. 



Development and application of water near San Bernardino, Colton, and 

 B-iverside, Cal., J. B. Lippinxott ( Water Suppihj and Irrig. Papers, U. S. Geol. Sur- 

 vey, Nos. 59,60, pp. 141, pU. 11, figs. 14)- — These papers describe the general condi- 

 tions of water supply in this important and densely populated region, where the 

 value of water for irrigation is very high. The topics discussed are general location 

 and topography, soil, climate, crops, and water supply. Descriptions are given of the 

 streams tributary to the region, the irrigation systems, artesian wells, and pumping 

 plants. "The data are of particular interest because of the developments made dur- 

 ing the dry years which culminated in 1890. Every possible Rxjiedient was resorted 

 to for economizing or increasing the supply of water; tunnels were driven into the 

 hdls, dams were built to bed rock in the canyons, and wells were dug or drilled 

 throughout the valleys. Almost every conceivable device for pumping water has 

 been employed and great ingenuity displayed in bringing water to the orchards and 

 more valuable crops. The details of some of the works and wells have been brought 

 together by Mr. Lippincott, and form an exhibit of results accomplished under con- 

 ditions where water has great value." 



