ON THE FORM OF SILOS. 27 



stated, the first separate silos built were rectangular, shallow struc- 

 tures, with a door opening at one end. The silos of the French 

 pioneer siloist, August Goffart, were about 16 feet high and 40x16 

 feet at the bottom. Another French silo built about fifty years ago, 

 was 206x21% feet and 15 feet deep, holding nearly 1,500 tons of 

 silage. Silos of a similar type, but of smaller dimensions, were 

 built in this country in the early stages of silo building. Ex- 

 perience has taught siloists that it was necessary to w r eight the 

 fodder heavily in these silos, in order to avoid the spoiling of 

 large quantities of silage. In Goffart's silos, boards were thus 

 placed on top of the siloed fodder, and the mass was weighted at 

 the rate of 100 pounds per square foot. 



It was found, however, after some time that this heavy weight- 

 ing could be dispensed with by making the silos deep, and grad- 

 ually the deep silos came more and more into use. These silos 

 were first built in this country in the latter part of the eighties; 

 at the present time none but silos at least twenty to twenty-four 

 feet deep are built, no matter of what form or material they 

 are made, and most silos built are at least twenty-four to thirty 

 feet deep or more. 



Since 1892 the cylindrical form of silos has become more and 

 more general. These silos have the advantage over all other 

 kinds in point of cost and convenience, as well as quality of the 

 silage obtained. We shall, later on, have an occasion to refer to 

 the' relative cost of the various forms of silos, and shall here 

 only mention a few points in favor of the round silos. 



1. Round silos can be built cheaper than square ones, because 

 it takes less lumber per cubic foot capacity, and because lighter 

 material may be used in their construction. The sills and stud- 

 dings here do no work except to support the roof, since the lining 

 acts. as a hoop to prevent spreading of the walls. 



2. One of the essentials in silo building is that there shall be 

 a minimum of surface and wall exposure of the silage, as both 

 the cost and the danger from losses through spoiling are thereby 

 reduced. The round silos are superior to all other forms in 

 regard to this point, as will be readily seen from an example: A 

 rectangular silo, 16x32x24 feet, has the same number of square 

 feet of wall surface as a square silo, 24x24 feet, and of the same 

 depth, or as a circular silo 30 feet in diameter and of the same 

 depth; but these silos will hold about the following quantities of 



