CASKS ; COOPERAGE. The making of casks, barrels, butts, hogsheads, tubs, &c., is, up to the present time, almost wholly a han dicraft employment. The peculiar shaping of the pieces of wood, the fitting them together, and the mode of binding them with iron hoops, —are all effected without the aid of anything which deserves the name of machinery. Yet when we consider how mathematically exact all the angles and curves must be, it would seem to be a branch of manufacture peculiarly fitted for the application of machinery. Accordingly, we find that patents are fre quently taken out for cask-making machinery. One such patent, by Mr. Brown, obtained twenty or thirty years ago, relates to a system of machinery, of which one part cuts the edges of the staves; another part cuts the groove or chine for receiving the head ; a third part cuts the head into a circular shape: a fourth bevels the edge of the head ; and a fifth gives a smooth circular surface to the exterior of the cask.
Davison and Symington's patent respecting casks, taken out in 1844, relates to the value of a rapid current of heated air, not only in drying wood, but in removing fungous impuri ties which often accompany damp-wood. They recommend that, in making a cask, instead of drying the wood in the ordinary way before using, by which it is difficult to bend without blistering, it should be cut up quite green, and shaped into staves and heads—due allow ance being made for shrinkage. The pieces are easily bent in this state ; and being tem porarily fastened together, they are exposed to a rapid current of heated air, which carries off all the moisture, and shrinks the pieces to the proper size.
The same patentees also use hot air to cleanse casks after using : a method which they consider to be more effectual and cheaper than the use of steam, which is ordinarily em ployed in the great breweries. In order to remove from the interior of the cask any fun gus or impurity which cannot be removed by the heated air, the patentees use a peculiar kind of chain, which enters at the bung-hole, and is worked about by moans of machi nery.
Mr. Robertson, a cooper of Liverpool, took out a patent in 1819 for a series of machines of rather complicated character, for making casks and similar vessels. One piece of ap
paratus is intended to plane, at one time, both sides of the staves which are to form the curved part of the cask ; giving a convexity to one surface and a concavity to the other sur face of each piece of wood. A second piece of apparatus planes the edges of the staves, giving to each edge the particular slope neces sary for the staves to assume a circular ar rangement when placed edge to edge. A third machine compresses all the staves together in a circular form, and forces the ends within the hoops which are to bind them together, Another machine presses together the pieces of wood which are to form the head of the cask, cuts them into a circular form, and bevels the edges. A fifth piece of apparatus cuts the groove in which the head is fitted to the cask; and another punches the holes in the iron hoops. Thus, according to the patentee's plans, every part of a cask is made by machi nery.
Mr. Samuel Brown patented in 1840 a mode of making metallic casks. The cask is formed of a parallelogram of sheet iron or other metal, turned up into a cylindrical form, with an or dinary lap joint. The head of the cask is formed of a circular piece of metal, cut out and turned up all round the edge ; this being forcibly driven into the cylindrical barrel, has rivets placed at intervals of four or five inches all round, which are rivetted through the bar rel and through the turned up edge of the head. The other end of the cask, called the moveable head, is made like the first, but at tached in a different manner ; in this case projecting ears of metal are rivetted at proper intervals around the cylinder ; and the heads of these rivets being within the cylinder, serve as stops to prevent the head of the cask from being driven in too far. This second head being forced into its place, the ears are bent down upon the edge of the cylinder and over the raised edge of the head, thereby retaining I it firmly in its place. The joints are to be made fluid-tight with any of the ordinary paints or cements.