1758 Repokt of Fakmeks' Institutes 



of cement, depending npon the size of the stone and the coarse- 

 ness of sand. In other words, the coarser the material used, the 

 less cement is required to fill all of the voids. 



Hard cinders where they are convenient for the work, make 

 an excellent and economical concrete. The fine material in them 

 need not he sifted ont ; in fact, most cinders furnish enough fine 

 material to take the place of sand entirely in most farm con- 

 struction. I have hnilt two huildin^s with cinders and cement 

 alone with perfectly satisfactory results. To demonstrate the 

 proportions of any kind of material required, provide a water- 

 tight receptacle and measure accurately, fill level fidl with the 

 coarser material to he used, then carefully measure in water 

 enough to fill the vessel. The proportion of water to the size of 

 the vessel will indicate the amount of sand required to fill all 

 of the voids in the coarser material, then l)y mixing this coarser 

 material with the indicated proportion of sand, again filling the 

 vessel wntli the mixture, and then with water, the proportion of 

 water used will indicate the amount of cement required with 

 this mixture of these materials to make an artificial stone. 



MixiisrG 



A convenient way of measuring materials for the mixing hoard, 

 is to provide a hox '21 inches long, 12 inches wide, and IIV2 

 inches deep, with no hottom, and handles on either end. This 

 hox will hold just two sacks of cement, which is ahout the amount 

 used for the ordinary hatch in farm work. After filling it on the 

 mixing-hoard it is emptied hy lifting the hox off the materials; 

 beginning with the coarser material and finishing with the 

 cement. Thorough mixing is essential to success and it must 

 first he done while the materials are dry. The only safe guide 

 to determine the completeness of the mixture is its color. If 

 it is streaked it is not mixed thoroughly no matter how many 

 times it has hcen turned. Use a shovel and shovel from the 

 bottom of the pile, sifting the materials off the edge of the shovel 

 upon the apex of a new pile. If this method is followed, three 

 turnings will usually he found sufficient. Successful concrete 

 work requires tliat tlie materials he placed in the form as quickly 

 as possible after they are mixed. 



