lo Aug., 1911-] 



Silo Construction. 



569 



in bulk by teing washed. Both chiy and loam are drawbacks, particularly 

 the former. Attention should next be paid to the cement. Tests of 

 cement are rather too delicate and complicated for the ordinary man, .so 

 that reliance must be placed on the brand. On the whole, the locally-made 

 cements are to be preferred to the imported makes, as they are all reliable 

 and slow setting, a desirable feature for the amateur builder, while the 

 imported brands, though very good in some ca.ses, are not so in all. A 

 ■cask or barrel of cement weighs about 375 lbs. ; a cubic foot packed 

 weighs 120 lbs. In colonial makes, it is generally supplied in bags, 

 two of which go to the barrel. As a rough-and-ready rule, one barrel of 

 cement goes to the cubic yard of concrete. It must be borne in mind that 

 one cubic vard of gravel or metal is required for one cubic yard of con- 

 crete, the cement and sand serving only to fill up the voids. 



For mixing, a plat- 

 form or smooth space 

 is required. A mixing 

 board can readily be 

 knocked up out of ordi- 

 nary boards. Frames 

 also are made out of 

 boards to hold, say. 

 half a cubic yard of 

 metal, one-sixth of a 

 cubic yard of sand, and 

 one-twelfth of a cubic 

 yard of cement, or in 

 any desired propor- 

 tions. The sand, 

 which should be drv. 

 is first put in its frame 

 on the mixing board, 

 and then the cement is 

 added. The two are 

 thoroughly mixed by 

 l»eing turned o\er 

 with shovels, and the 

 mixture is spread as 

 thinlv as possible in 

 one layer over the 

 Ix.'ard. The gravel or 

 m.etal is then mea- 

 top (jf the cement and sand. Mixing by 

 d me, after which water is added ; a water- 

 bnsl for the latter purpose. Shovelling is con- 

 that is, when in a semi- 

 slojipy 



for biutrer 



sured. 

 sho\el 



mXCRETE SILO. 



and spread on 

 ling is thoroughly 

 ing can with a rose is lh< 



tinued until the whole mass is sufficiently wetted 

 dry condition, but not enough so as to run or \m 



A batch may be, as mentioned above, half a cubic vard, or 

 work, one cubic yar<i. Shelter from (he wind is advisable, otherwi.se there 

 will be loss of cement. The concrete should f)e mixed as near its final posi- 

 tion as possible ; it must be u.sed at once, and not allowed to stand over the 

 dinner hour, and. under no circumstances, until the next day. If it is u.sed 

 in bulk, it mav be lightlv rammed into position with a small-headed ram- 

 mer. Care should l)e taken in ramming not to keep it up longer than the 

 vcommencenient of setting, a matt<'r of a few minute.s onlv : nor ^'^ould 



9.>54. .\ 



