SCIENCE OF THRESHING. 69 



With clay moistened to the consistency of stiff dough 

 seal up all the openings thoroughly, save the oil hole. 

 Plug this up with a stick, packing the clay around it in 

 funnel shape, to pour the metal in. After all is in 

 readiness, remove the stick with care that no clay falls 

 into the hole. 



To be poured successfully, the metal should be of 

 a temperature to burn wood. To test it insert a stick 

 of wood occasionally into the melting pot, and when 

 the babbitt makes the stick smoke or turn black, it is 

 of the right temperature. 



When pouring, the metal should be turned in as 

 fast as it will run through the opening, to insure its 

 filling the lower half of the box; do not stop until 

 the box is full, as the metal chills very quickly and 

 will not unite with fresh metal, after it has once set. 



After pouring, remove the clay and break the box 

 apart by driving a cold chisel between the halves, 

 dressing off the points of the broken fins formed in 

 the notches of the shimming. If the lower half of 

 the box is not filled, enlarge the openings in the 

 shimming and try again. 



Relieve the shaft by scraping some of the babbitt 

 from the inside of the box, removing the most near 

 the inside edges; in bolting the cap on, insert an 

 extra piece of shimming at the box edges, otherwise 

 the box would be too tight if left as babbitted, and 

 would heat. 



By inserting a stick in the oil hole before the 

 metal has cooled, it will form an oil hole and save 

 drilling or punching one. 



