KURAL ENGINEERING. 593 



For an outfit of the third type, consisting of one 80 h. p. engine and other 

 equipment, the total capital outlay is estimated at 28,800 rupees, and the annual 

 working expenses at 9,986 rupees. It is estimated that with 2 shifts of men 

 this outfit will plow 6 acres per day to a depth of from 16 to 18 in., at an aver- 

 age cost per acre of 14 rupees. 



The total capital outlay for a small outfit of the fourth type of the cheapest 

 possible construction, consisting of one 18 h. p. engine and other equipment, is 

 estimated at 12,150 rupees, and the annual expenses at 3,867 rupees. It is esti- 

 mated that with 2 shifts of men this outfit will plow 1 to li acres per day. to a 

 depth of from 16 to 18 in., at an average cost per acre of 28 rupees and 4 annas. 



For an outfit of the fifth type the total capital outlay is estimated at 3,196 

 rupees and the annual working expenses at 1,452 rupees. It is estimated that 

 this outfit will plow i acre per day in black cotton soil to a depth of from 16 to 

 18 in. and can be worked 150 days in a year, plowing ST? acres at an average 

 cost of 39 rupees per acre. 



Summing the results of all the investigations, the first type Is considered 

 applicable only for shallow plowing ; the second type is considered the most 

 elficient and economical of all, with the third type second; the fourth is not to 

 be recommended on account of its complicated arrangement, difliculty in opera- 

 tion, and general inefliciency ; and the fifth type is considered simple and reli- 

 able but slow and expensive. 



New machines for vineyard spraying, G. Coupan {06nie Civil, 63 (1913), 

 2^0. 2, pp. 31-33, figs. 11). — Recent developments in vineyard spraying machinery 

 are described and diagrammatically illustrated. The types include both power 

 and liquid sprayers and machines both drawn and carried by animal power. 



Stress analysis of circular tubes, B. Haukelid {Engin. Rec, 67 {1913), No. 

 24, pp. 669-672, figs. 11). — An analytical and graphical determination of stresses 

 in tunnel sections under symmetrical, unsymmetrical, and variable loading is 

 given. 



Welding' iron and steel, A. Tornquist (Amer, Thresherman, 1.5 (1913), No. 

 12, pp. 6, 88, figs. 9). — The author gives practical instructions for the welding, 

 annealing, and hardening of iron and steel, which may be applied to general 

 forge work on the farm. 



Silo construction in Nebraska, L. W. Chase (Nebraska Sta. Bui. 138, pp. 96, 

 figs. 73). — This bulletin deals with the location, planning, erection, care, and 

 cost of wood, pit, clay block, concrete block, and solid concrete silos, describes 

 specific examples, and gives bills of material for each. 



In connection with the construction of concrete block silos a design is fur- 

 nished for a homemade concrete block machine and cuts shown of 2 silos 

 made with such a machine. 



The cost data show that the pit silos described cost per ton capacity from 

 75 cts. to $2.27, of which from 16 to 76 cts. is for material. The total cost for the 

 concrete block silos was from $1.93 to $3.94 per ton capacity, and the cost of 

 materials from $1.61 to $2.66. The clay block silos had a total cost of $1.70 to 

 $3.46 per ton capacity, of which the material cost from $1.37 to $1.88, and the 

 solid concrete silos had a total cost of from $2 65 to $4.25 per ton capacity, of 

 which the material cost from $1.64 to $3.09. A bill of materials for a 119-ton 

 wood stave silo is given showing a total cost of $269-31. 



Numerous tables of designing and working data are included. 



Silo construction in Nebraska, L. W. Chase (Neb7-aska Sta. Bui. 138, popu- 

 lar ed., pp. 20, figs. 9). — A popular edition of the above. 



Vacuum cleaning', M. S. Cooley (Heating and Ventilating Mag., 9 (1912), 

 Nos. 2, pp. 39-1,5, figs. 7; 12, pp. 15-17, figs. 2; 10 (1913), Nos. 1, pp. 11-16, figs. 

 6; 2, pp. 13-19, figs. 10). — The ideal requirements of a vacuum cleaning system 



