RURAL ENGINEERING. 891 



15 (1913), pp. 813-820) .—In this paper, read before the American Society for 

 Testing Materials, the author gives the results of 5 or 6 years' experiments on 

 the action of the salts in alkali waters and of various oils on cement concrete. 

 In these, 1 : 3 sand briquettes of normal Lehigh Valley cement were immersed in 

 1 per cent solutions of the various salts, among which were sodium chlorid, mag- 

 nesium sulphate, calcium sulphate, sodium sulphate, and sodium carbonate, for 

 periods ranging from 7 days to 2 years. 



The results indicate that even very dilute solutions of the salts of magne- 

 sium and the sulphates in general have a destructive action on concrete. 

 Further tests of the generally proposed remedies to prevent such action indi- 

 cate that they do not appreciably retard it. The results in general, however, 

 indicate the desirability of employing low alumina cements in concrete struc- 

 tures subject to such destructive action. 



Experiments by immersing the briquettes in engine oil, cylinder oil. and black 

 mineral oil showed no harmful results with the first 2 oils, but a complete 

 disintegration of the briquettes occurred in the black oil after being immersed 

 between 6 months and 1 year. 



Flow of water in pipes, W. L. Durand {Power, 38 (1913), No. 1, p. 20, fig. 



1). — A set of curves on logarithmic paper is given showing the relation between 



quantity of water, friction head, and size of pipe. The curves may be reduced 



to the formula F=0.4 d "^-^ h °-^^, from which the following formulas may be derived: 



V 69 v^-^^ 73 v^-^^ 



V=0.327 <Pv,v=3.0G ^, h= ,ji.2i — ' and d= ' jsi.sr 'f in which F= cubic feet 



per minute, 'P=velocity in feet per second, ft=friction head in feet per 100 

 ft., and d=actual internal diameter of pipe in inches. 



Windmills in India, H. D. Bakeb {Daily Cons, and Trade Rpts. [U. S.], 



16 {1913), No. 172, pp. 489-491) .—Attention is called to the open field for the 

 profitable employment of windmills in lifting water for irrigation in India. 

 From results of experimental work in Madras by A. B. Chatterton it is stated 

 that American windmills are not strongly enough constructed for work in 

 India, the most serious defects, aside from minor breakages, being due to the 

 poor fitting of the valve in the pump chamber. Much trouble would be obviated 

 if the pivots on which the flap valves turn were made larger and fitted into 

 better designed sockets. 



A 16 ft. windmill, mounted on a 40 ft. tower and fitted with an S in. pump, 

 will cost, when erected over a well, about $500. . Assuming the cost of main- 

 tenance at $1.75 per month, 6 per cent interest on the capital expended, and 10 

 per cent for depreciation, the total cost of operation is $8.41 a month. Such a 

 plant will do the work of 2 pairs of cattle, and if fitted with 2 pumps will be 

 equivalent to 3 pairs of cattle. 



The principles of fuel oil engines, C. F. Hieshfeld {8ci. Amer. Sup., 76 

 {1913), Nos. 1959, pp. 46, 41, figs. 5; 1960, pp. 61-64, figs. 9; 1961, pp. 14, 15).— 

 This paper, read before the American Society of Agricultural Engineers, deals 

 with the chemical and physical basis of the operation of fuel oil engines. A 

 review of certain physical phenomena, including evaporation, vaporization, and 

 boiling, is followed by a consideration of fuels which are either complex mix- 

 tures of hydrocarbons of widely differing properties or are less complex dis- 

 tillation products made therefrom. 



Vapor pressure curves are given for a number of pure hydrocarbons and for 

 gasoline and kerosene of 66° and 45° B. gravities, respectively. The gasoline 

 curve indicates the boiling point under atmospheric pressure at a temperature 

 of 145° F. but the kerosene curve indicates that at 175° the vapor pressure of 

 this fuel is only about 0.14 atmosphere. Other curves are given showing the 



