28 



BULLETIN 229, U. S. DEPARTMENT OF AGRICULTURE. 



the nature of the gum; the older the gum the smaller the charge. 

 Even with " virgin dip" the still is only filled to three-fourths of its 

 capacity, while with dip and scrape from four or five year " boxes," 

 which foams considerably, only about one-third the capacity of the 

 still is used. If the material rises into the still head there is danger 

 of it forcing an exit between collar and still head and setting fire to 

 the platform. 



The still body is about two-thirds as high as wide, with a rounded 

 top and a slightly concave bottom, the latter permitting the rosin to 



FIG. 5. Arrangement of apparatus in turpentine still. 



drain thoroughly. The still head is generally spherical x and is con- 

 nected with the worm by two sections of pipe called the "arm" and 

 " gooseneck." The worm makes about 6J turns in a wooden tank 

 holding the condensing water, leaving the tank by means of a short 

 pipe called the tailpiece. The entire apparatus is made of sheet 

 copper. For a 20-barrel still, the side, top (" breast"), and collar of 

 the still proper are made of 14-gauge copper, the rosin spout of 11- 

 gauge, and the bottom of 4-gauge copper. The worm and connect- 

 ing pipes are made of 18-gauge copper. 



1 Several ibrms of still bead are in use. 



