414 



Missouri Agricultural Report. 



tamp it until the water rises to the top and the body Avill slightly 

 quake. 



To get a good finish on the face of concrete, run a shovel or a 

 garden hoe, bent in a direct line with the handle, down between each 

 layer of concrete and the form, pull the concrete out slightly and pour 

 a 1 to 3 mortar into the space and then tamp thoroughly back into 

 place. If a particular good finish is desij:"ed, plaster the forms just 

 ahead of the concrete with a 1 to 3 or a 1 to 2 mortar. Thoroughly 

 spading and working the concrete next to the molds as it is placed 

 will produce a reasonably good but not always a smooth finish. A 

 good finish may be obtained on solid concrete by dressing off the 

 rougher edges by hand and then rubbing down the surface with 

 carborundum blocks, after which wash with cement paint — a thin 

 solution of water and cement. 



Where concrete is left unfinished until it has set, or over night, 

 the unfinished parts must be roughened, cleaned and wetted before 

 fresh concrete coming in contact with it is deposited. 



Coloring — Dry mineral colors affect the cement least and are 

 mixed in proportions given in the following table : 



Waterproofing — It is not an easy task to make concrete absolutely 

 watertight. It is a very dense mixture indeed that water cannot find 

 its way through. Either the whole body of the concrete must be 

 rich and dense or else a rich, dense surface an inch or two thick must 

 be applied on the side from where the water comes, or apply tar- 

 papers or felts to the surface. 



Apply the waterproofing to that side of concrete from where the 



