913 



NEEDLE MANUFACTURE. 



NEGATIVE QUANTITIES. 



911 



and exposed to a cherry-red heat. When this degree of heat has been 

 attained, the crucible is withdrawn, and the needles are dropped into 

 cold water or oil ; from this they are taken out and put upon an iron 



delicate touch, aided by a quick eye, she draws out laterally to the 

 right, those which have their eyes on the right, and to the left, those 



Fig. 2. A Comb of double-needle wires. 



jilate almost red hot, where they are turned about so as to cause the 

 heat to apply equally to all ; and as fast as the needles become of a 

 blue colour, they are removed as being of a proper temper. 



Such of the needles as now appear crooked are straightened on a 

 small anvil by blows from a hammer : a process conducted by women, 

 and called hammtr-atraiyhtening. 



The needles are next ranged in parallel rows upon a coarse cloth, 

 which has been smeared with a mixture of oil, soft soap, and fine emery 

 powder. In this cloth from 40,000 to 50,000 needles are rolled up, 

 and twenty or thirty of these rolls are placed together in a machine 

 like a mangle. The rolling to which they are here subjected is con- 

 tinued, by means of steam or water power, for two and sometimes 

 three days, during which time the cloth wrappers being worn out, 

 require to be once or twice replaced by new ones. The finest needles 

 require forty hours of this kind of friction. When taken out, after 

 rolling, the needles are perfectly bright. 



Fig. 3. Succescive stages of a Needle. 



The excellence of modern needles consists, in part, in the process of 

 ilrillin : i, to which the best kinds are subjected. When the eyes of 

 needles are only stamped and pierced, their edges are apt to cut the 

 tlirt.il ; but by a subsequent drilling, the eye becomes as smooth and 

 p.ili.-hcd as any other part. To effect this, the needles are blued, or 

 heated to a particular temper ; then countersunk, to bevel the edges of 

 the. eye ; then drilled by means of delicate wires which pass through the 

 eyes; then ground on small revolving gritstones, to give roundness to 

 the head of each needle ; and then pulislted by pressure against 

 revolving wooden wheels covered with buff-leather, and touched with 

 ling paste. The different stages in these highly-finished needles 

 are nhown in .//;/. 4. 



The iiccillfs. whether of the finer or commoner kinds, are now 

 examined for the rejection of any that may be imperfect ; and then 

 shaken in a flat tray until all become parallel. But, though parallel, 

 they are not regular; seeing that the heads of gome are in one 

 direction, and those of others in another. They are brought into 

 regularity in a simple Imt remarkable way. A girl, seated at a window, 

 preads out the needles before her, parallel with the window ; by a 



AIIT8 AMI SU. MV. VOL. V. 



Fig. 4. Drilled-eycd Needles. 



which have their eyes on the left ; and then combines the two parcels. 

 Women then separate the needles into parcels of 25, and wrap them 

 up in blue papers at the rate of 3000 needles in an hour. Labels are 

 pasted on the papers and dried ; 20 papers are packed into a parcel; 

 and from 10 to 50 parcels are made up into a bundle, for the wholesale 

 trade. If for exportation, the bundles are placed in soldered tin 

 boxes. A bundle of 10,000 needles, of the kind called No. 6, forms 

 a compact mass (i inches long, 3^ wide, and 2 in thickness. 



Kedditch, which was only a village a few years ago, is now a con- 

 siderable town, almost all the inhabitants of which live by the needle 

 trade. Eight or ten thousand persons are employed in the works in 

 the town and neighbourhood; and these support the bulk of the 

 remaining part of the population. The work is conducted on two 

 different systems, the factory and the domestic. On the factory 

 system a large building is constructed, supplied with steam or water 

 power, and with efficient machines of all kinds ; and iu this building 

 all the processes are conducted. On the domestic system, country 

 people, living within 'a few miles of Redditch on all sides, come to 

 the warehouses or manufactories in the town, fetch away a packet of 

 wires or needles, take it home, do a portion of the work, and return 

 the packets to the warehouses. Some do the annealing, some the 

 pointing, some the piercing, some the drilling, &c. ; each person, (of 

 whom more than half are females) being competent for only one branch 

 of the manufacture. The product of the whole neighbourhood, even 

 several years ago, was supposed to reach 100,000,UOO needles per 

 week ! 



NEGATIVE QUANTITIES. This subject is considered, as a part 

 of the most complete algebra, in the article ALGEBRA. In the present 

 article we confine ourselves to such a view as may be sufficient for 

 ordinary algebra. 



In the oldest treatises on algebra which exist, there is mention of a 

 modification of quantity unknown in arithmetic, called negative quan- 

 tity, as distinguished from positive. In the Viga Ganita [ VIOA GANITA, 

 Bioo. Div.] we find this distinction and the rules for its use precisely 

 as in modern treatises. One of the commentators says that negation is 

 contrariety ; and the ' Liliwati ' contains the geometrical interpretation 

 of a negative line namely, a line measured in the direction contrary to 

 that of a positive line. The commentator says that I'atna is fifteen 

 yojanas east, and Allahabad eight yojanas west, of a place called 

 Varanasi ; " the interval or difference is twenty-three yojanas, and is not 

 obtained but by addition of the numbers. Therefore, if the difference 

 between two contrary quantities be required, their sum must be taken." 

 Surely it will be said that algebra began in a strange confusion of 

 ideas ; but yet the fault is rather in expression than in conception. An 

 art was in existence presenting undoubted means of discovering truth, 

 commencing with a generalisation of which the use was obvious, but 

 not the meaning. In Diophantus we find the common rule announced 

 as a definition (without even a previous notice of the distinction of 

 quantities) in terms as broad as the following : " Aciij/i? M Aciif/ip 

 iroA\a7rA.a<nao-0fra TOI?I fnrapju'," &c. literally, " Defect upon defect 

 repeated, makes existence." In Mohammed Ben Musa [ALGEBRA] the 

 rules are announced in the same way, though the separate existence of 

 posiiive and negative quantities does not seem to be assumed : it must 

 be remembered that this work was written for popular use. The 

 European promoters of algebra, with the exception only of Vieta, 

 adopted the use of two species of quantities, positive and negative, 

 with the explanation above noticed. Vieta not only avoided the 

 negative quantity, but, so far as he could, dispensed with subtractive 

 terms and subtraction itself. He discards the double nature of quau- 

 tities in the words " Plus autem vel minus uon constituuut genera 

 diversa." 



It is not our intention to follow the earlier algebraists through their 

 different uses of negative quantities. These creations of algebra 

 retained then- existence, in the face of the obvious deficiency of 

 rational explanation which characterised every attempt at their theory. 

 Newton and Euler distinctly admit the existence of the quantity less 

 than nothing : the latter asserts that a man who has no property, and 

 is in debt 50 crowns, would only have nothing if any one else made 

 him richer by a gift of 50 crowns, and therefore begins with 50 cruwns 

 Ices than nothing. Elementary treatises for the most part try to 

 append an explanation of mga ive quantities to an aigclia which is 



3 N 



