AGRICULTURAL ENGINEERING. 795 



The author recommends that charcoal should be heated before administration to 

 drive off the absorbed gases. 



The disappearance of pathogenic organisms from manure and compost, 

 A. Gartner {Ztschr. Hyg. n. Infektionskrank., 28 {1898 , No. 1, pp. 1-19). 



Notes on an experimental study of the disinfecting power of common soap, 

 J. Alexandrow {Russk. Arch. Patol. Klin. Med. i Bakt., 4 {1897), No. 6, pp. 676-685). 



Experimental studies on the disinfecting power of ordinary soaps, A. Sera- 

 fini {Arch. Hyg., 33 {1S9S). Xo. 4, pp. 369-399).— A number of experiments are 

 reported. 



The investigation of Dr. Koch on animal diseases in Africa.. E. L. {Rev, Gen. 

 Agron., 7 {1S9S), Xo. 11, pp. 4S5-491). — A brief summary. 



The literature of veterinary medicine and allied sciences, R. Schotz (Die Lit- 

 teratur der Vetinar wissenschaft mid verwandter Gebiete. Berlin, 1S9S: rev. in Zischr. 

 Fleisch u. Milchhyg., 9 {1S9S), Xo. ,2, p. 37).— The period covered is from April 1, 1889, 

 to July 1, 1898. 



AGRICULTURAL ENGINEERING. 



Loss from canals from filtration or seepage, L. G. Carpenter 

 {Colorado Sta. Bui. 48, pp. 36, jig. 1). — A series of observations were 

 made on " stretches of canals in the Flatte Valley and Cache la 

 Pondre Valley near Fort Collins and several in the San Litis Valley, 

 and one canal on which automatic records were kept for 2 years. The 

 method of measurement was essentially the same in all cases, namely, 

 to measure the amount flowing in the canal at different points, and 

 then to compare the increase or decrease in the amount of water in the 

 canal after allowing for the water taken out by laterals between the 

 points of measurement.*' 



The results are discussed in detail and summarized as follows: 



"(1) The losses from evaporation are relatively insignificant compared with the 

 seepage losses from most canals. In the cases most favorable to evaporation and least 

 favorable to seepage the evaporation is nut over 15 per cent of the seepage. 



"(2) In the case of reservoirs it was concluded in bulletin 45 that the seepage was 

 less important than the evaporation. This is different from the results found in 

 ditches, not because the evaporation is less, but because the seepage is much more. 



" (3) The losses are sometimes enough to cover the whole canal 20 ft. deep per day. 



"(4) The loss in clay soils is less than in sandy or gravelly soils, but rarely as 

 small as 3 in. daily. 



"(5) The loss is greater when water is first turned in than after the bed has 

 become saturated. 



Sometimes the canals are found to gain for the whole or part of their length 

 or the canals may act as drains. This is more likely to be the ease when the canal 

 is deep in the ground, when crossing lines of drainage, or when located below other 

 ditches or irrigated tracts. 



" (7) In the prevailing Colorado soil, when not intercepting seepage, the loss may 

 be put provisionally at from 1 to 2 ffc. per day over the whole surface of the canal. 

 In clay soils it is less, but still nearly one-halt' as much. 



"(8) The loss in carrying water in small quantities is relatively larger than iu 

 carrying large amounts. The increased depth of water means increased lea! 

 but the carrying capacity increases faster than the leakage. 



" (8a) From the standpoint of economy it is wasteful to run a small head. It is 

 more economical to ruu a large head for a short time. In the management of small 

 ditches the time system of distribution can be introduced to advantage, saving time 

 and labor as well as water. 



