Scouring by the cask

After being worked during 18 or 20 hours under the tables, the needles are taken out of the packets, and put into wooden bowls, where they are mixed with sawdust to absorb the black grease upon their surfaces. They are next introduced into a cask, fig. 764. , and a workman seizing the winch P , turns it round a little; he now puts in some more sawdust at the door, A , B , which is then shut by the clasps G G , and continues the rotation till the needles be quite clean and clear in their eyes; which he ascertains by taking out a sample of them from time to time.