mOCESS OF EXTRACTING Oil,. 405 



generally accomplished by four, or half-past four 

 o'clock in the afternoon. The copper again hoils by 

 half an hour after five or six, and is boiled off 

 by seven or eight in the evening. The men cm- 

 ployed in this service, consisting of about six per- 

 sons, alternately watch in the night by couples. 

 Those on watch commence about two in the mor- 

 ning to empty the copper, which done, they again 

 fill it from the starting-back, which is always made 

 ready the night before. Thus the process goes on, 

 until the whole cargo is finished. 



Ey means of three coolers, severally capable of 

 contiiining at least twice the quantity of oil pro- 

 duced from one boiling of blubber in the copper, each 

 can be allowed, in turn, to stand undisturbed up- 

 Vv'ards of twenty-four hours. Thus, v. hile one is in 

 the act of being filled, another stands to cool and 

 settle, and the third is drawn off. If the backs 

 be twice this size, or four times the capacity of the 

 copper, every one will require two days to be filled 

 by one copper, and after being filled, may subside 

 during two or three days undisturbed. Even two 

 backs in number, of this capacity, would admit of 

 an interval of twenty-fovu* hours each, after being fill- 

 ed, before it would be necessary to begin to empty it. 



Thus prepared and cooled, the oil is in a market- 

 able state, and requires only to be transferred from 

 the coolers into casks for the convenience of convey- 

 ance to any part of the country. Each of the cool- 



