28 
BULLETIN 229, U. S. DEPARTMENT OF AGBICULTUBE. 
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 cone axe 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 6^ 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 lS-gauge copper. 
1 Several ibrms of still head are in use. 
