1919] RURAL ENGINEERING. 89 



The prevention and treatment of hog cholera, J. H. McNeil and T. W. 

 Mux.;. i.\. ./. Dept. Agr. Bid. 13 {WIS), pp. 513-594 ).— This is a general dis- 

 cussion of the subject. 



Shote pox, Velu (Rev. Gen. Me"d. IV/.. 21 (1918), No. 310-317. pp. 186-145, 

 figs. 4; COS. in Vet. Rev., 2 (1918), No. 4, pp. 450. J f 51).— The etiology, sympto- 

 matology, pathologic anatomy, diagnosis, prognosis, and prophylaxis of shote pox 

 are discussed. Inoculation by scarification of variolitic pulp has been used for 

 two years by the author with excellent results. 



Uremia of acarian origin in horses, Lkneveu (Rec. Me"d. V6t. t 93 (1917), 

 No. 11, pp. 477-481; trans, in Yet. Jour., U, (1918), No. 512, pp. 69-72; Vet. Rec, 

 80 (1911), No. 1532, pp. 200. 201). — A report upon a condition observed in 

 horses affected with generalized mange. In studies of 20 animals affected with 

 generalized mange, albuminuria was found in eight. 



A Physaloptera from the dog, with a note on the nematode parasites of 

 the dog in North America, M. C. Hall and M. Wigdor (Jour. Amer. Vet. Med. 

 Assoc., 53 (1918), No. 6, pp. 733-144, flff^. 6). — A new species taken from the dog 

 at Detroit, Mich., is described as Physaloptera vara. 



RURAL ENGINEERING. 



The gas tractor in eastern farming, A. P. Yerkes and L. M. Church (U. S. 

 Dept. Agr., Farmers' Bui. 1004 (1918), pp. 27, figs. 3).— This publication sum- 

 marizes detailed reports received from over 250 experienced tractor owners in 

 New York State during 1917 and the spring of 1918. The operating conditions 

 upon which the reports were based were rolling country with a comparatively 

 heavy stony loam soil and heavy clay subsoil. Very diversified farming was 

 practiced on all farms reporting, at least half a dozen different field crops being 

 grown. More than one-third of the entire acreage was devoted to hay. 



The reports indicated that the greatest advantage of the tractor lies in its 

 ability to perform the work in a shorter time than when horses are employed. 

 The saving in man labor was considered next in importance, and the ability to 

 do better work in plowing and preparing the soil was placed third. Under dis- 

 advantages the reports indicated the inability to use the tractor satisfactorily 

 until the top soil is well dried. On heavy soil packing of moist soil resulted, 

 and unsatisfactory work on hilly and rough land, especially in stony fields, was 

 frequently the case. It is noted that 84 per cent of the cases reporting indicated 

 that the tractor was a profitable investment, and of this number over one-third 

 increased the acreage farmed. 



With reference to size of outfit the general conclusion is drawn that the 

 2-plow tractor does not possess in an adequate degree the greatest advantage of 

 tractors in general, and that the 3-plow tractor is distinctly the favorite among 

 owners of farms of 151 or more crop acres. The reports indicated an annual 

 repair charge during the first three years of use of a tractor on New York farms 

 of nearly 4 per cent of the first cost. It is thought that this will increase 

 during later years of operation. 



The area covered per day of ten net working hours in plowing wirh the 

 tractors used on New York farms was 4.5 and 6.25 acres for the 2- and 3-plow 

 outfits, respectively. The average cost per acre plowed for gasoline, oil. and 

 grease was about 99.5 cts. where gasoline was used, and 49 cts. where kerosene 

 was used, with an allowance of 2 cts. per acre for gasoline used in warming up. 

 The approximate costs of plowing an acre with 2- and 3-plow tractors, based on 

 average costs of $775 and $1,050, respectively, and a life of Si years of 54 

 working days per year, are given as $2.26 and $2.06, respectively, for gasoline 

 and $1.76 and $1.56 for kerosene. 



