AGRICULTURAL ENGINEERING. 495 



12-foot windmill, the price of the mill and 90-foot tower being $160, 

 and the capacity of such a grinding- plant would be many times ^\ hat 

 would be demanded for a herd of 30 cows." 



Silage and the construction of modern silos, F. H. King ( Wis- 

 consin Sia. Bui. 83, pp. 68, figs. 28). — This bulletin discusses the value 

 of silage as a feeding stuff; the essential conditions for preserving 

 silage; the details of construction, cost, and efficiency of silos of dif- 

 ferent kinds; the selection and culture of crops suitable for ensiling; 

 the preparation of silage; and the losses which occur in the prepara- 

 tion and feeding of silage. 



' ' The problems of silage and silo construction have been studied now continuously 

 for nearly 10 years. Two bulletins on the subject have been issued [E. S. R.,9, p. 

 393], and the present one embodies the knowledge which has been gained through 

 a personal inspection of more than 200 silos, one-half of which were visited the past 

 year, together with the conclusions regarding the essential conditions necessary to 

 the making and jireserving of good silage which have been reached through experi- 

 mental studies extending over 7 j^ears." 



The cylindrical silo has generally proved most satisfactor3\ Various 

 tj'pes of it, constructed of brick, stone, and wood, and lined and ven- 

 tilated in different ways, as well as stave, pit, and rectangular silos, are 

 described. 



It appears that the unavoidable loss, i. <?., "the loss of feeding value 

 which can not be prevented in the interior of a silo with air-tight lin- 

 ings when filled in the best practicable manner," may be as low as 2 to 

 4 per cent and in good practice need not exceed 4 to 8 per cent. An 

 account is given of comparative experiments on this point with 3 types 

 of silos — (1) a silo (with doors) made of Washington cedar staves accu- 

 rately beveled and tongue-and-grooved, (2) a silo (without doors) made 

 of 2 by 4 pine staves not beveled or tongue-and-grooved, (3) a galvan- 

 ized iron cylinder with water-tight bottom and sides. The first and 

 second silos were without bottoms, but stood on a level cement floor. 

 The silos were filled with corn, cut in short pieces, at the same time 

 and in the same way. 



"When full, the silos were covered with 3 layers of acid and waterproof paper cut 

 to a circle to fit closely, and upon this was placed a layer of sand about 5 in. deep. 

 The silos stood in the warm plant house from August 29 until INIarch 1, when they 

 were opened." 



The losses from the top laj-ers of silage in the 3 silos were 50.75, 

 49.71, and 9.21 per cent, respectively; middle layers, 13.15, 14.98, and 

 7.01 per cent; bottom layers, 31.75, 26.16, and 0.51 per cent. 



"The large losses from the bottoms of the two stave silos were due to air entering 

 between the ends of the staves and the cement floor, and the greater losses from the 

 [cedar stave] silo at both the bottom and toj) were due to the additional leaks al)out 

 the doors. 



"The metal silo was absolutely air-tight everywhere excejit at the top, and the 

 three cases illustrate in an extremely forceful way how important it is to exclude the 

 air from the silage. 



