NEEDLE MANUFACTURE 



411 



sand interstratified between the layers, and this mixture is besmeared frith rape-seed 

 oil. Fig. 1565 represents one of the rolls or packets of needles 12 inches long, 

 strongly bound with cords. Those packets are exposed to the to-and-fro pressure of 

 wooden tables, by which they are rolled about with the effect of causing every needle 

 in the bundle to rub against its fellow, and against the siliceous matter, or emery, 

 enclosed in the bag. Fig. 1560 represents an improved table for polishing the needles 

 by attrition-bags. The lower table, M M, is moveable, whereas in the old construction 

 it was fixed; the table c has merely a vertical motion, of pressure upon the bundles, 

 whereas formerly it had both a vertical and horizontal motion. Several bundles may 

 obviously be polished at once in tho present machine. The table M M, may be of any 

 length that is required, and from 24 to 27 inches broad; resting upon the wooden 

 rollers, B, B, B, placed at suitable distances, it receives a horizontal motion, either by 

 hand or other convenient power ; the packets of needles A, A, A, are laid upon it, and 



1560 



over them the tables c, c, c, which are lifted by means of the chains K, K, K, and the 

 levers, L, L, i, in order to allow the needles to be introduced or removed. The see-saw 

 motion forces tho rouleaux to turn upon their own axes, and thereby creates such 

 attrition among their contents as to polish them. The workman has merely to distri- 

 bute these rolls upon the table M, in a direction perpendicular to that in which the 

 table moves ; and whenever one of them gets displaced, he sets it right, lifting by the 

 help of the chain the loaded table. The table makes about 20 horizontal double vibra- 

 tions in the mimite; whereby each bundle, running over 24 inches each time, passes 

 through 40 feet per minute, or 800 yards in the hour. 



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, fy. 1561, and a workman seizing the winch p, turns it round a 

 little ; ho 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 are quite clean and clear in their 

 eyes ; which he ascertains by taking out a 

 sample of them from time to time. 



Winnowing is the next process, by means 

 of a mechanical ventilator similar to that by 

 which corn is winnowed. The sawdust is 

 blown away, and the grinding powder is 

 separated from the needles, which remain 

 apajt clean and bright. 



The needles are in the next place arranged 

 in order, by being shaken as above described, 

 in a small, somewhat concave, iron tray. 

 After being thus laid parallel to each other, 

 they are shaken up against the end of the tray, and accumulated in a nearly upright 

 position, so that they can be seized in a heap and removed in a body upon a pallet- 

 knife, with the help of the forefinger. 



