SHOT MANUFACTURE. The larger kinds of shot, such as pistol bullets and rifle balls, are generally cast in a mould, one at a time. Shot of the next smaller size, such as swan shot, are often produced by casting several at a time ; there is a double mould formed something like a pair of nut-crackers, which, when closed, exhibits a range of little moulds into which the melted lead can be poured ; and, when open, allows the shot so made to be removed from the mould. A ruder kind is sometimes made by shaking a number of small fragments of lead together in a bag or box, by which the corners or rough edges are worn away. In another mode of manu facture, a piece of thin lead is cut up into Title cubes, and these are placed between two flat stones, the upper of which works over the lower ; so that by the combined pressure and movement the cubical fragments are worn to a cubical shape.
But the most remarkable mode of making shot is by granulation, which is the plan now adopted for the larger portion of shot now used. The shot are made either over the mouth of a deep well or shaft, or at the top of a lofty tower, so as to provide a vertical descent of one or two, hundred feet. The elegant tower (intended originally as a shot-tower, but now applied to other purposes) near the foot of Waterloo Bridge, illustrates the latter of the two methods. In some of the shot works on the banks of the, Tyne, an abandoned coal shaft is employed. There are about fifteen sizes of shot made by the granulation method, varying from -} to of an inch in diameter.
The lead has a little arsenic added to it, and is melted in a furnace or pot. Over the vertical shaft is placed a tripod or stand, and upon this a kind of colander, pierced with holes suitable in size to the shot to be made.
A layer of dross from the surface of the melted lead is laid over the holes in the colander, to act as a kind of sieve or strainer, and to separate the liquid lead into small trickling streams before it reaches the holes. The melted lead is poured into the colander by a ladle ; and it speedily falls as a sort of silvery rain down the shaft, into a vessel of cold water at the bottom ; the lead is found to separate into almost perfectly spherical drops or shots ; and these shots when cold, are brought up from the vessel below, dried on steam heated plates, and separated into sizes by sifting. The irregular or ill-shaped shot are separated from the others by a beautiful contrivance ; they- are made to roll down an inclined plane of smooth iron; and when they get to the bottom, the well-shaped shot have acquired an impetus which sends them into a box or cell, several inches distant; whereas the ill-shaped shot, having descended the inclined plane in an irregular way, have acquired very little velo city, and fall into a cell or Vox not so far dis tant as the other. By carefully adjusting the slope of the inclined plane, this separation of good from had shot is effected with surprising accuracy. The shot are then placed in a kind of churn or revolving barrel, into which a little black lead is also placed : and they are revolved iu the churn until they become po lished and black leaded. They are lastly tied up in hags containing 28 lbs. each.