SIXThJaNNUAL year book — PART VIII. 743 



As the silo was partially cut in two on the side where the openings 

 were left, it was necessary to reinforce it between the doors. The strong- 

 est, cheapest, and most satisfactory way to do this was to ceil that |jde 

 of the silo with an extra thickness from the bottom to the top, using 

 half-inch lumber, the same as that with which the silo was lined. The 

 doorways were, of course, left in the middle of this extra ceiling and 

 the spaces between the doors were thus covered with two thicknesses, 

 with no broken joints for 14 feet, as shown in Cut 17. The ends of the 

 boards of this inner lining broke joints on three studs so that all of 

 the strain at the end of these boards should not come at one stud. These 

 irregular ends were filled out with short pieces so that the edge of the 

 extra thickness would come in a straight line. Since this inner ceil- 

 ing left a jog of a half inch, the thick edge of common shingles was 

 butted against the ends of the half-inch boards, thus running the extra 

 thickness down to a feather-edge and making an apparently even sur- 

 face on which to lath. (Cut 17.) 



The silo was then lathed with common four-foot lath, breaking 

 joints as shown in Cut 18, and nailing the lath solid to the half-inch 

 ceiling without furring out. It is usally recommended in lathing silos 

 that the edges of the lath be cut on a bevel so that when nailed to the 

 wall a dove-tailed joint is formed for the mortar, or that the lath be 

 set out on furring" strips so that the mortar may clinch behind the lath. 

 Experience shows that this is entirely unnecessary= 



The plaster was made of one part Portland cement to two parts of 

 good sharp sand. Two coats of this mortar were us.ed making the 

 plaster a full half-inch thick over the lath. The second coat extended 

 continuously from the bottom of the brick work to the top of the silo, 

 uniting the foundation and the superstructure and giving an air-tight 

 wall for the entire silo. 



Four doors were made of two thicknesses of common flooring run 

 in opposite directions with tar paper between. These doors are each 

 20 inches wade, 2 14 feet high, and are four feet apart. The top of the 

 upper door is five feet below the plate, but by the time the silo is opened 

 the silage has usually settled nearly to the top of the upper door so 

 that but little silage has to be removed before the door can be taken 

 out. The size and location of the four doors are shown in Cut 19 and 

 a section of one of them in Cut 16. 



Authorities on silo construction have erroneously stated that for silos 

 20 feet in diameter and 30 feet deep, three thicknesses of half-inch lumber 

 are required to give sufficient strength. This silo is .30 feet in height 

 above the foundation and as the pressure of silage at this depth is 330 

 pounds per square foot there is a tensile pull on the sides of the bottom 

 foot of a silo of these dimensions of 3,300 pounds. In this lower foot to 

 resist this strain, there are. of course, two boards each one-half inch 

 thick and six inches wide making a total area of six square inches of 

 lumber. On account of the great tensile strength of wood it was thought 

 that this one layer of half-inch lumber would be sufl[icient to withstand 

 the. strain. To determine if this were true, the silo as shown in Cut 15 

 'was filled and after standing six weeks did not show the slightest sign 

 ^of giving in any particular. 



