KURAL ENGINEERING. 89 



*' virus fixe " which was treated for 24 hours with a 5 per cent solution of phenol 

 was able to produce typical rabies after a period of 10 days' incubation. 



Hydrophobia in the Philippines, F. W. Dudley and E. R. Whitmoee 

 {Philippine Jour. Scl, B. Med. Sci., 5 (1910), No. 5, pp. ^55-Ji59, pi. i).— "The 

 authors have shown . . . that rabies occurs among dogs in the Philippines, (a) 

 by finding Negri bodies in the brain tissue of 2 dogs killed for suspected rabies; 

 (b) bj'^ carrying the virus from the brains of one of these dogs through 7 pas- 

 sages in rabbits, rabbits of the seventh passage dying in 9 days of typical ex- 

 perimental rabies; (c) by demonstrating the presence of Negri bodies and Lentz 

 passage bodies in the brain tissue of these rabbits up to the third passage. 



"It was also shown that rabies occurs in the human in Manila, (a) by ob- 

 serving a case that was clinically typical rabies; (b) by carrying the virus from 

 the brain of that case through 3 passages in rabbits, the rabbits of the third 

 passage dying of typical experimental rabies in about 2 weeks; (c) by demon- 

 strating the presence of Negri bodies and Lentz passage bodies in the brain 

 tissue of 3 rabbits up to the third passage." The authors have further "suc- 

 ceeded in bringing a fixed virus from Saigon to Manila in animals and also 

 in neutral glycerin in a refrigerator. The virus brought in both ways has 

 retained its full virulence since its arrival in Manila." 



Entero-hepatitis (amcebiasis), B. F. Kaupp (Amer. Vet. Rev., 39 (1911), 

 No. Jf, pp. -'flO-^16, figs. 5). — This paper includes studies of the disease in a 

 flock of 60 fowls of which 25 had died at the time of the investigation. 



RURAL ENGINEERING. 



Power and the plow, L. W. Ellis and E. A. Rumely (Garden City and New 

 York, 1911, pp. 318, pis. 22, figs. 25). — This book discusses in a nontechnical 

 way the various sources of power for farm implements, with special attention 

 to traction plowing. Data are summarized on the history of plowing with both 

 animal and mechanical power, the mechanical principles of plows and plowing, 

 conditions affecting plowing audthe choice of plows, and the draft of plows and 

 other implements ; the efficiency for draft puiiwses, particularly plowing, of the 

 horse, the steam tractor, and the internal combustion tractor, the adaptability of 

 cable plows, auto plows, the general purpose motor, and a combination of animal 

 and mechanical power to tillage operations ; and the outlook for traction farming 

 in the future. Descriptions are given of the various types of tractors and plows 

 and their qualifications for different kinds of farming are discussed in detail. 

 Specifications of leading gas tractors and a bibliography are appended. 



Tests of centrifugal pumps, B. P. Fleming and J. B. Stoneking (Neiv 

 Mexico Sta. Bui. 77, pp. 81, figs. 3Ji). — In conducting experiments in 1908-9 

 (E. S. R., 22, p. 792) to determine efficiency and relative cost data for pumping 

 plants under given conditions, the unexpected low efficiency ratings for cen- 

 trifugal pumps (in no case higher than 51.8 per cent), suggested experiments to 

 determine the exact relative efficiency of pumps under varying heads and at 

 varying speeds. 



Eleven pumps with discharge pipes varying from 1^ to 6 in. were tested under 

 the same physical conditions, each being rated at varying speeds and pumping 

 against different lifts. For each specific condition the efficiency was determined, 

 the percentage rating being the ratio of the useful horsepower to the electrical 

 horsepower supplied the pump. The resultant curves under the various condi- 

 tions under which each test was made were platted for each pump. The signifi- 

 cant feature of these curves is that for each pump tested there is a point of 

 maximum efficiency, that is, each pump did its best work against some par- 

 20296°— No. 1—12 7 



