LEAD-SHOT 79 



Lead imported into the United Kingdom in the Year 1872. 



Quantities 



Description of Lead tons 



Lead ore ...... 14,560 



Lead, pig and sheet .... 69,841 



Lead manufactures . . . . 441 



British and Foreign Lead exported in the Year 1872. 



British Foreign 



Description of Lead tons tons 



Lead ore 1,004 1,404 



Pig lead 33,403 691 



Lead, rolled, sheet, piping, and tubing . 10,927 



Lead manufactured 4 



lEAD-SHOT. (Plomb de Chasse, Fr. ; Schrot, Flintenschrot, Ger.) The origin 

 of most of the imperfections in the manufacture of lead-shot is the too rapid cooling 

 of the spherules by their being dropped too hot into the water, whereby their surfaces 

 form a solid crust, while their interior remains fluid, and, in its subsequent concretions, 

 shrinks, so as to produce the irregularities of the shot. 



The patent shot-towers originally constructed in England obviate this evil by ex- 

 posing the fused spherules after they pass through the cullender, to a large body of 

 air during their descent into the water-tub placed on the ground. The highest erec- 

 tion of this kind is probably at Villach in Carinthia, being 240 Vienna, or 249 English 

 feet high. 



The quantity of arsenic added to the mass of melted lead varies according to the 

 quality of this metal ; the harder and less ductile the lead is, the more arsenic must 

 be added. About 3 pounds of either white arsenic or orpiment is enough for one 

 thousand parts of soft lead, and about 8 for the coarser kinds. The latter are em- 

 ployed preferably for shot, as they are cheaper, and answer sufficiently well. The 

 arsenical alloy is made either by introducing some of this substance at each melting ; 

 or by making a quantity of the compound considerably stronger at once, and adding 

 a certain portion of this to each charge of lead. If the particles of the shot appear 

 lens-shaped, it is a proof that the proportion of arsenic has been too great ; but 

 if they are flattened upon the side, if they are hollowed in their middle, called 

 cupping by the workmen, or drag with a tail behind them, the proportion of arsenic is 

 too small. 



The following is the process prescribed by the patentees, Ackerman and Martin. 

 Melt a ton of soft lead, and sprinkle round its sides in the iron pot about two shovel- 

 fuls of wood ashes, taking care to leave the centre clear ; then put into the middle 

 about 40 pounds of arsenic to form a rich alloy with the lead. Cover the pot with 

 an iron lid, and lute the joints quickly with loam or mortar to confine the arsenical 

 vapours, keeping up a moderate fire to maintain the mixture fluid for three or four 

 hours ; after which skim carefully, and run the alloy into moulds to form ingots or pigs. 

 The composition thus made is to be put in the proportion of one pig or ingot into 1,000 

 pounds of melted ordinary lead. When the whole is well combined, take a perforated 

 skimmer, and let a few drops of it fall from some height into a tub of water. If they 

 do not appear globular, some more arsenical alloy must be added. 



Lead which contains a good deal of pewter or tin must be rejected, because it tends 

 to produce elongated drops or tails. 



From two to three tons are usually melted at once in the large establishments. The 

 surface of the lead gets covered with a crust of oxide of a white spongy nature, some- 

 times called cream by the workmen, which is of use to coat over the bottom of the cul- 

 lender, because without such a bed the heavy melted lead would run too rapidly through 

 the holes for the granulating process, and would form oblong spheroids. The mount- 

 ing of this filter, or lining of the cullender, is reckoned to bo a nice operation by the 

 workmen, and is regarded usually as a valuable secret. 



The cullenders are hollow hemispheres of sheet-iron, about 10 inches in diameter, 

 perforated with holes, which should be perfectly round and free from burs. These 

 must be of an uniform size in each cullender ; but of course a series of different cul- 

 lenders with sorted holes for every different size of lead-shot must be prepared. The 

 holes have nearly the following diameters for the annexed numbers of shot : 



No. sV of an inch. 



1 & 



2. ...... 58 



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