MAKING COMMON FRAMING JOINTS 



67 



grain. Such work is illustrated by the cutting of joints such 

 as the tenon and mortise joint, in which the mortise is 

 chiseled out. 



A chisel is ground and whetted in the manner described for 

 sharpening a plane-iron (Sec. 26). 



Working Instructions for Seed Tester: 



Stock: Four 1" x 3-1/2" x 6" hard pine S2S. 



Four V x 6-1/4" x 6" matched flooring S2S. 

 Six-penny (6d) nails and 1-1/2" brads. 



45. Purpose of Seed Tester. The following instruc- 

 tions are for the seed tester, or germinating box, which is used 

 to test the fertility of seeds. 

 As the soil must be moist for 

 this purpose, the box must be 

 made strong to withstand the 

 effect of the moisture, which 

 has a tendency to open up 

 joints and change the shape of 

 boards by warping or winding. 



It is for this reason that the 

 corners of the box are mace 

 with a lock joint, and that the 

 tongues of the joint are glued 

 and mailed together (Figs. 87 

 and 93). 



The upper surface of the soil 

 is blocked off into squares that 

 each one may be used for an individual seed or a group of 

 seeds. These squares are determined by a cord strung be- 

 tween the opposite sides of the box (Fig. 87). 



FIG. 92. Chiseling across the 

 grain. 



