AGRICULTURAL ENGINEERING. 287 



Entero-hepatitis or blackhead of fowls, F. D. ("iikstkk and A. Kobix {Ddauxire 

 ><lit. L'jit. IMO, pp. i:o-'!i), Ji(jx. ■)'). — This disi'ase, which has been known as occurring 

 in turkeys, is now reported as attacking chickens. A detailed report is given on the 

 technical methods employed in preparing and studying pathological tissue. In 

 affected livers certain bodies were seen in some of the cells, which are suspected of 

 being young stages of the jiarasitic organism which causes the disease. 



Notes on parasites, 55-57, C. \V. Stiles and A. Hassall ( U. S. Depjt. Afjr., 

 Bui-eau of Anhnal Lidastr;/ C/jvv S4, pp- 4)- — The authors describe a pupa-like .stage 

 of Ornithodoros megiiini and discuss the synonymy of BodjihlhiK ai(straH<> and B. hovis. 

 Slron(j!ih(S contortiis and Ct/xtlccrcns teiiuicoUls are reported as having been found in a 

 specimen of mule deer which died at the National Zoological Park. 



On disinfection, W. L. Macke.vzie ( Vet Jour.,5;^ {1901), Xo. 308, pp. 100-108). — 

 The author discusses the practical value for disinfecting purposes of light, fresh air, 

 sulphurus acid, corrosive sublimate, chlorid of lime, lysol, carbolic acid, and formal- 

 dehyde. 



Stable disinfection, F. P. (tokiiam {Rhode Lilaiid Stati' lid. Agr. Rpf. 1900, pj). 

 315-32;^). — The author gives a brief account of tuberculosis, glanders, and other dis- 

 eases, with notes on disinfection of stal)les after outbreaks of these diseases by means 

 of formalin, carbolic acid, carl>ol-sulpharic acid, creolin, and chlorid of lime. 



The laws of the Grand Duchy of Hessen relating- to indemnities for 

 animals affected -with anthrax, blackleg, and hog cholera, Lorexz {ZtKckr. 

 ThUrmed., 5 {1901), Xo. 1, pp. 12-63). — This article contains copies of regulations 

 relating to the subject, an elaborate discussion by the author on the sanitary meas- 

 ures to be adopted in outbreaks of these diseases, and on the methods of preventive 

 inoculation which promise to yield the best results. 



AGRICULTURAL ENGINEERING. 



The carrying capacities of irrigation canals, S. Fortier ( Utah Sta. Bid. 71, 

 pp. 5.5, Jigs. 42). — This is a report of (54 experiments made during the summer of 1897 

 on irrigation channels varying in size from small ditches carrying a few miner's 

 inches to large canals carrying as high as 225 second-feet, and including nearly everj' 

 form of ditch common to western America. 



"The object sought was to ascertain as accurately as po.ssible the existing con- 

 ditions of ditches and canals that had been in operation for a number of years. In 

 order to obtain the volume which flowed in any particular ditch and compare it with 

 some well-known empirical formula, such as Kutter's or Chezy's, it w'as necessary to 

 ascertain the slope of the surface of the water, the sectional area of the water, the 

 mean velocity, and the ratio betweeji the water area and the wetted perimeter." 



Other objects which the author had in view was to ascertain the form which chan- 

 nels assume when acted upon by water and the atmosphere and to determine the 

 values of the coefhcient of roughness (n) under different conditions. 



The discharge was measured either by a current meter or by a Cippoletti trapezoidal 

 weir, special precautions being taken to secure the conditions necessary for accurate 

 measurements. The current meter measurements recorded are in every case the 

 mean of from 3 to 6 readings. The average cross sections were obtained "by plat- 

 ting in different colors on a large scale the three or more cross sections taken in the 

 Held. A new perimeter was then adopted which represented the average of all those 

 jilatted. Its length was found by a j>air of dividers and the area of the average sec- 

 tion by a planimeter. 



"The slope of a canal represented by the fall of a given portion, usually from 50 

 to 300 ft., divided ]jy the distance, was determined by a new Buff and Berger IH in. 

 level and a leveling rod reading to thdiisaiidths of a foot. 



8847— No. 3—01 7 



