RURAL ENGINEERING. 585 



recently purchased Buff Orpiugtous at the poultry plaut ou the college farm, as 

 a result of which the average egg production for the year was but 25 per cent 

 of the theoretical. The percentage of fertility of the eggs was low, about 60, 

 although apparently good vigorous male biixls were used. The disease was 

 found to be very hard to overcome and it is concluded that in dealing with it 

 the best method lies in the destruction of the affocted fowls. 



In an attack of roup that broke out at the plant in January about the only 

 birds affected were those in the pens laying the heaviest. Control measures 

 consisted in the isolation of affected fowls as soon as detected. Most of the 

 affected birds were treated and recoveiy resulted in a week or ten days. 



The necessity of meat inspection of poultry, with, especial regard to 

 tuberculosis, A. Breueb {Ilusszemle, 8 {1913), No. 11, pp. 81-83; abs. in Berlin. 

 Tierarzil. Wchnschr., 30 (1914), No. 12, p. 206). — The importance of examining 

 the viscera of poultry, in addition to other parts, is pointed out. Where this is 

 not done great danger exists of spreading the disease. At the Budapest abattoir 

 8,337 head of poultry shipped from Servia were examined, and of this number 

 1S8 were tubercular, of which 183 were diseased only in a few organs, espe- 

 cially in the digestive tract. In the Budapest market tuberculosis in fowls is 

 said to be present to the extent of from 6 to 13 per cent. 



RURAL ENGINEERING. 



Wood pipe for conveying' water for irrigation, S. O. Jayne {U. 8. Dept. 

 Agr. Bui. 155 {1914), pp. 40, pis. 4, pjs. 7).— This bulletin deals with the de- 

 sign, construction, durability, possibilities, and limitations of continuous and 

 machine-banded wood pipe f-or several classes of service and is intended to be 

 of interest to irrigation engineers, owners of irrigation works, water power com- 

 panies, and water departments of municipalities. The studies reported included 

 the inspection of many pipe lines throughout several western States, interviews 

 and correspondence with manufacturers, builders, and operators of wood pii^e, 

 and a review of published data on the subject. 



As regards the durability of wood pipe, data are presented to show that the 

 length of time any pipe will last can not be accurately predicted without a 

 thorough knowledge of all the conditions involved. '' With pipes buried in the 

 ground the wood will endure longest where the air is most nearly excluded either 

 by a high internal pressure which completely saturates it or by a deep covering 

 of very fine soil. ... In contact with the soil wood pipe decays more rapidly 

 under a light head than it does under heavy pressure, and other things being 

 equal, it usually decays more rapidly in a porous open soil, such as sand or 

 gravel, than it does in a fine soil of silt or clay, because the finer soil is more 

 effective in excluding the air. Experience appears to indicate also that wood 

 decays more rapidly in a loamy soil, rich in humus or partially decayed organic 

 matter, than it does in one containing little or none. . . . 



" The life of exposed pipes may be prolonged by promptly stopping all leaks 

 as they develop and by keeping the exterior diy. The decay of buried pipes 

 has also in some instances been arrested by removing the covering and leaving 

 them exposed. . . . Where pipes are to be placed in contact with the soil, and 

 where the internal pressure is not sufficient to insure complete saturation of 

 the staves, it is probable that their durability may be increased by treating with 

 some preservative. . . . 



" Contrary to the theories commonly held thirty years ago, it has been found 

 that the durability of wood l)ipe is usually dependent on the life of the wood 

 rather than ou the life of the bands. . . . Corrosion of the bands . . . usually 

 occurs most rapidly where pipes are buried and the backfill is wet, under con- 



