COPPEB MANUFACTURE. 



COPPICE. 



HI 



" in all iu part*, it exhibit* the mult of almost every operation of hi* 

 workshop." To make this article piece of iheet copper i* taken, 

 nther laager than the intended circumference of the kettle, and some 

 i wider than iU depth. The surface of thi* piece of copper, for 



about an inch at each end, ii then brightened by filing, and one end it 

 rat into to the depth of about an inch, and at interval* of about an 

 inch, with a pair of shear*. Every alternate portion of the cut edge i* 

 then toned a little back, ao that when the plate U bent round into a 

 cylindrical shape, the uncut end may be laid between the alternate 

 tongue* or portion* of the out edge, and embraced, aa it were, by them. 

 A mixture of borax and wider i* then applied to the joint, which ia, 

 after soldering, hammered upon a steel mandril or stake, until the Mam 

 btygm smooth, and i* beaten down to the thickneu of the adjoining 

 portion* of thn plate. A perfect cylinder being thu* formed, the next 

 operation i* to turn it inward* in a doping direction for a space of 

 about two inch**, to form the top of the kettle, or that portion which 

 M ^(.j. from the shoulder at the top of the cylindrical side of the 

 Teasel to the edge of the opening to which the cover is fitted. Thin is 

 done by hammering upon an anvil of suitable ahape. About an inch 

 of the lower end i* then turned inward in the same way, and cut with 

 the abean into tongue*, which are bent back alternately in the same 

 manner a* thoee at the end of the plate had been. A piece of sheet 

 copper cut to fit the end of the cylinder, *o a* to form the bottom of 

 the kettle, i* then inserted and united to the cylinder by the name 

 proems* a* that described fur the first joint. The vessel is then pirHtd 

 in diluted sulphuric acid, after which it i* planished to brightness, 

 the mark* of the hammer being rendered imperceptible by the inter- 

 vention of a piece of old moreen, or other woollen stuff, between the 

 surface of the copper and the stake or anvil on which it i* laid. The 

 h'd of the kettle U dished by stamping it in a die ; the handle ia cast ; 

 and the spout, after being soldered up and rounded a little on a 

 mandril, is finally shaped upon lead with which it baa been filled, and 

 afterwards soldered or riveted into it* place. Copper tea-urns and 

 saucepans are formed by soldering and hammering in a similar manner, 

 the former being in general finished with a beautiful colour, produced 

 by the application of sulphate of copper or Roman vitriol, previous to 

 the planishing or burnishing. 



There are several different modes of forming copper piping out of 

 sheet metal. In one of these, the edges of the sheet, which is curved 

 round a mandril, are made to meet without overlapping, and united by 

 hard solder ; in a second, they overlap, and are united by soft solder ; 

 in a third they overlap, and are secured by rivets ; in a fourth, the 

 edges are folded together, one being bent outwards and the other 

 brought over it and turned into the acute angle formed between the 

 outside of the tube and the turned back edge, the whole being sub- 

 sequently made close and firm by hammering ; while in a fifth, both 

 edge* of the pipe are turned back and covered with a strip of sheet 

 metal, the two edges of which are turned in like the outer edge of the 

 joint last described. The bending of such pipes into curved forms, as 

 for the spiral coil in the sugar-pan described above, is a curious opera- 

 tion. Any attempt to bend such a tube while empty would be certain 

 to impair its shape, and would probably occasion ite fracture. To 

 obviate this difficulty the pipe is, before bending, filled with lead, or 

 some soft metallic alloy which will melt at a temperature which will 

 not injure the tube. Being thus filled, the pipe may be treated as a 

 solid bar of metal, and safely bent into any required form by suitable 

 machinery ; and when the desired curvature is gained, sufficient heat is 

 applied to cause the contained metal to melt and flow out of the pipe. 

 A patent was taken out a few years ago, for a mode of using up old 

 worn-out rollers, such a* those employed in calico-printing. The 

 cylinders are to be bored truly, rolled or drawn out to the form of 

 tubing, and annealed. 



The use of copper sheathing for ships, an application which occa- 

 sion* a very large demand for this metal, is alluded to under SMII-- 

 BCILDIKO. The articles BRASS ; BRONZE ; and BELL-CASTING, treat of 

 some of the most important manufactures of the alloys of copper. Of 

 some of the minor articles of manufacture, in the composition of 

 which copper forms a chief constituent, an account is given under 

 BCTTOX ; and COCK. 



We add a few words concerning the trade and statistics of copper. 

 No effective attempt has ever been made to ascertain the actual pro- 

 ductiveness of the mines in this country ; and all that \ hitherto 

 known on the subject i* derived from partial inquiries of individuals. 

 By this mean*, however, a tolerably accurate account has been Uken 

 of the produce of the copper mines in Cornwall, reaching back to 1771, 

 with the exception of a few intermediate years, the returns of which 

 are wanting. Since 1821 similar accounts have been procured of the 

 produce of other mines in the United Kingdom. The annual produce 

 of the Corniah mines rose from about 3400 tons in 1771, to 000 tons 

 in 1800 ; 7000 ton* in 1820 ; and 12,000 tons in 1835. Since the last 

 named year the yield ha* not advanced in equal ratio. The total 

 quantity of metallic copper obtained at the (melting works of England 

 and Wales, wa> 1 4,000 ton* in 1835 ; since which year there has been a 



st. ,.!;, .:. MM, 



The supply from South Australia is becoming important. It wan in 

 184S that twelve minors began operation* at the Burra Burra copper- 

 mine* in that colony; in the beginning of I860 there were more than 

 a thousand employed, supporting a population of five thousand persons. 



In the intervening period of fourteen yean, the Bum Burra yielded 

 128,000 ton* of copper ore, from which 26,000 ton* of metallic copper 

 were obtained, worth from two to three millions sterling, according to 

 the state of the market A small portion of the produce wa* shipped 

 to England in the state of ore. 



During the U*t three yean, the import* of copper ore and regulus 

 into Great Britain have been a* follows, from different countries : 



From Bpln . 

 Cuba 

 Chill . 

 Atutnll* . 

 ,, All ele 



.- : 



1857. 



'j . _ 



13.030 



IC.SSJ 



39, m 



8.48 



K.sjs 



SS.094 



V 



Including copper in a partly manufactured state, the total in 1858 

 amounted to 128,280 cwta. The exports of metallic copper, in tin- 

 same three yean, presented the following figures : 



Brick and pig copper 

 Sheet and nail copper 

 Wrought copper 



185. 



Cwt. 

 1J1.9SS 

 HT.ITl 



28,716 



1857. 



Cwt. 

 141,910 

 571,536 



65,419 



1S58. 



Cwt. 



134,818 



303,810 

 68,114 



This i* irrespective of the copper contained in the article* of brass 

 manufactured. The declared value of the copper and copper good* 

 exported in 1858, was no less than 2,698,8361., averaging about 10. 

 per cwt. British India is the largest purchaser of these goods. 



COPPEK-NICKKL. [NICKL.] 



COPPERAS. [iHoif, Prototulphatt of.] 



COPPICE, a wood or plantation of various kind* of trees, which 

 shoot up from the root when cut down, and which are periodically cut 

 down before they acquire any considerable size. The most common 

 trees planted or used for this purpose are the oak, the chestnut, the 

 maple, the birch, the ash, and the willow. The hazel and the alder 

 are also frequently planted in coppice, the former in dry and chalky 

 soils, the latter in moist and marshy situations. Timber tree* are 

 generally allowed to grow in coppice, or more properly the coppice is 

 the underwood where the timber is the principal object. There U a 

 doubt, however, whether it ia judicious to allow many tree* to stand 

 where there is a ready sale for coppice wood. The quick return of the 

 latter overbalances the greater price of old timber. In consequence of 

 this opinion, large trees fit for ship-building, which require a long 

 time to arrive at the required size, are becoming scarce ; and many 

 woods, once thickly studded with majestic trees, are reduced to mere 

 coppice wood. The value of a woll-managed coppice U considerable 

 where the produce can be readily manufactured into useful articles, 

 and carried to a good market. Ash hoops, hop-poles, chestnut gate- 

 hurdles, and sheep-hurdles are the principal articles manufactured or 

 prepared in a newly-cut coppice. What is of no use for these purposes 

 is made into faggots for fuel, where this i* scarce, or converted into 

 charcoal, which ia more easily transported. A good coppice will bear 

 to be cut down every eight or nine years, and will thua be worth, 

 according to situation, from 6/. to 151., per acre, or even moro. 

 sold to those who undertake to cut and prepare the wood. 



Little attention is generally paid to the coppice, except win 

 fit to be cut, but this is a great mistake : with a little attention a cop- 

 pice may be doubled in value in a few years. It should be carefully 

 drained where the water has not a ready outlet. Where the most 

 profitable kinds of wood are deficient fresh planta should be supplied. 

 The whole should be kept well stocked, but not overstocked ; and the 

 priming-knife should be used where it appears necessary, especially 

 where hop-poles are in request, which usually bear a good price Hop 

 poles require a longer time to attain the proper size, and more room to 

 grow. For this purpose the coppice may be thinned out, without 

 Wing entirely cut down. When a coppice is cut, attention must be 

 paid to the manner in which the poles and rods are cut off from the 

 stem. They should be divided by a clean slanting cut with a very 

 sharp axe or bill-hook, so as not to shatter the stump which in left. 

 'I'll.' w,.iind will then soon heal over, and the stump will not IK* injunxl 

 by the wet and decay, as i* too often the case. When fresh ground is 

 planted for a coppice, it should always be previously t 

 drained. The extra expense of this will soon be repaid. Soot 

 may be planted at first as nurses and shelter to the oaks and 

 forest trees. In seven or eight yean the firs will have acquired a con- 

 siderable height, and may be thinned out or cut down ; they 

 shoot again from the root. The other trees may be left to grow 

 a few years longer, before they are cut down. After the first 

 cutting, attention must be paid to the stumps and all .-up 

 shoot* removed. In seven or eight years a thick coppice will Iw 

 formed, which will increase in value every tinu- it in out. and will pro- 

 duce a very good annual rent for land which might not have been 

 profitable in cuhi r as pasture or arable farms. The annual 



experiK ioe is trifling, and the regular returns are certain and 



profitable. When a portion of coppice is cut every year, no aa to hare 

 a regular rotation, the income is aa regular as that of any other part of 



