EXPERIMENT STATION BULLETINS. 



225 



When the form was properly placed, which was so that the top of 

 the finished pier should stand level and 5 inches above the general level 

 of the floor, or one inch above the top of the foundation walls, it was 

 carefully filled with a rather over wet mortar of sifted sand and 

 cement in the proportions of 5 to 1. In this operation the mortar 

 spread out somewhat beyond the lower edge of the form over the ground. 



Iron diamond wah 



feeJ door 





Most at the lumber m these stalls i^-Ceorgia Pme flooring Ubtei as z'xb" but really only 1^x6^. 



7\. 



1 

 1 



T 



,v.^»,ii,^._ ,v . J 



Fig. 13. 



In filling the form great care had to be exercised to remove the bubbles 

 of air which were inclined to lodge in the mortar against the walls 

 of the form and thus to leave holes of various sizes in the surface of the 

 piers. To remove these bubbles the masons carefully worked a trowel or 

 other thin steel tool back and forth in the wet mortar against the walls 

 of the form. 



In a few hours after filling (depending on the temperature) the 

 mortar sets sufficiently to remove the form, to be set for another pier. 



While the piers (2'in Fig. 14) were being built and given time to 

 properly ripen (or set), the section between the box stalls and the 

 29 



