412 



NEEDLE ORE 



The preceping five operations, of making up the rouleaux, rolling them under the 

 tables, scouring the needles in the cask, winnowing, and arranging them, are repeated 

 ten times in succession, in manufacturing the best articles ; the only variation being 

 in the first process. Originally the bundles of needles are formed with alternate layers 

 of siliceous schist and needles ; but after the seventh time, bran freed from flour by 

 sifting is substituted for the schist. The subsequent four processes, are, however, 

 repeated as described. It has been found in England, that emery-powder mixed with 

 quartz and mica or pounded granite, is preferable to everything else for polishing 

 needles at first by attrition in the bags ; at the second and following operations, emery 

 mixed with olive oil is used, up to the eighth and ninth, for which putty or oxide of 

 tin with oil is substituted for the emery; at the tenth the putty is used with very little 

 oil ; and, lastly, bran is employed to give a finish. In this mode of operating, the 

 needles are scoured in the copper cask shown in elevation infy. 1563, and in section 

 in fig. 1562. The inner surface of this cask is studded with points to increase the 

 friction among the needles; and a quantity of hot soap-suds is repeatedly introduced to 

 wash them clean. The cask must be slowly turned upon its axis, for fear of injuring 

 the mass of needles which it contains. They are finally dried in the wooden cask by 

 attrition with sawdust ; then wiped individually with a linen rag or soft leather ; when 

 the damaged ones are thrown aside. 



1563 



1562 



L 



1564 



1565 



1566 



At 



Sorting of the needles. This operation is performed in a dry upper chamber, kept 

 free from damp by proper stoves. Here all the points are first laid the same way ; 

 and the needles are then picked out from each other in the order of their polish. The 

 sorting is effected with surprising facility. The workman places 2,000 or 3,000 needles 

 in an iron ring, fig. 1566, 2 inches in diameter, and sets all their heads in one plane ; 

 then on looking carefully at their points, he easily recognises the broken one ; and by 

 means of a small hook fixed in a wooden handle, fig. 1564, he lays hold of the 

 broken needle, and turns it out. These defective needles pass into the hands of 

 another workman, who points them anew upon a grindstone, and they form articles 

 of inferior value. The needles which have got bent in the polishing must now be 

 straightened. The whole are finally arranged exactly according to their lengths by 

 the tact of the sorter with his finger and thumb. 



The needles are divided into quantities for packing in blue papers, by putting into a 

 small balance the equivalent weight of 100 needles, and so measuring them out without 

 the trouble of counting them individually. 



The bluer receives these packets, and taking 25 of the needles at a time between the 

 forefinger and thumb, he presses their points against a very small hone-stone of compact 

 micaceous schist, mounted in a little lathe, ho turns them briskly round, giving the 

 points a bluish cast, while he polishes and improves them. This partial polish is in 

 the direction of the axis ; that of the rest of the needles is transverse, which distin- 

 guishes the boundaries of the two. The little hone-stone is not cylindrical, but quad- 

 rangular, so that it strikes successive blows with its corners upon the needles as it 

 revolves, producing the effect of filing lengthwise. Whenever these angles seem to 

 be blunted, they are set again by the bluer. 



It is easy to distinguish good English needles from spurious imitations ; because 

 the former have their axes coincident with their points, which is readily observed by 

 turning them round between the finger and thumb. 



The construction of a needle requires numerous operations ; but they are rapidly 

 and uninterruptedly successive, so that a child can- trim the eyes of 4,000 needles per 

 hour. 



NEEDXiE ORE, or Aciculifc. A native sulphide of bismuth, copper, and lead, 

 in acicular crystals, found in Siberia. See AIKBMTB. 



