Coopering is the art of manufacturing casks, barrels, vats, and all kinds of circular or elliptic wooden vessels, that are bound together by hoops. There are several classes of coopers, some of whom carry on their peculiar branches distinctly, while others embrace the general manufacture in one establishment. The workmen, however, generally confine themselves to the particular line they have been brought up to, and in which they are consequently most expert. Thus we hear of "butt coopers," "rundlet coopers," "dry coopers," "white coopers," and "wine coopers." The work of the butt coopers chiefly consists in the manufacture and repair of casks for breweries, also puncheons and hogsheads. Their principal tools are very few, but they use these with so much dexterity and skill as to produce with surprising facility and dispatch the most solid, accurate, and substantial work. With an axe, an adze, two or three spoke shaves, and a bench, the cooper rapidly gives a new and perfect form to the material he operates upon. The bench consists simply of a stout plank 4 or 5 feet long, and 1 foot wide; it stands upon four feet, but considerably inclined, one end of the bench being usually about 2 feet high, and the other 6 or 8 inches lower.

On the bench are fixed "stops " and " keeps," for the purpose of holding the staves or other work. This cooper has also a large plane, called a jointer, which is usually fixed with its face upwards, and against which he forces the staves to shoot their edges to a smooth surface, (whether those edges are required straight or curved,) in order to make the "joints " or joinings of the staves come into perfect and hardly-pressed contact, when they are brought together to form the vessel. To describe all, or even the leading operations, of the cooper, would be uninteresting, because it is so openly and universally practised. We shall therefore proceed to notice, and that briefly, the nature of the occupations of the other classes of coopers mentioned; and afterwards we shall insert some patented improvements in the art, that appear to be deserving of notice. The rundlet coopers make use of the same tools, or nearly so, as in the branch of the trade last described, but of less dimensions. Their work consists chiefly in the manufacture of bottles, and small casks, for holding the products of the distilleries, besides numerous other purposes.

The dry coopers are employed in manufacturing sugar hogsheads, and casks of every size and quality, for holding dry goods; and as such vessels are seldom required air and water-tight, the workmanship is comparatively coarse to that of the butt and rundlet coopers, and the expense proportionally less. The white coopers manufacture all kinds of domestic utensils, such as are used for brewing on the small scale; for washing tubs, churns, pails, and a great variety of other work. To this branch of coopering is frequently added the coarser kinds of turnery for domestic use. The wine cooper's business consists chiefly in the removal and depositing of wines and spirits, which he is enabled to effect with greater security and convenience than other persons, who are not so intimately acquainted with the nature and strength of the vessels containing them. The bottling, storing, and packing of wines, and other liquors, belong to this branch of trade, besides the making of all repairs and alterations in the butts or casks which may be found necessary. Although the manufacture of backs and vats appears of a similar character to other coopering, yet it is usually made a distinct branch of business, and is performed by persons who call themselves back and vat makers.

From the variety of forms, and the immense strength required for some of the backs, as well as for the frame-work to support them, the knowledge and skill of the carpenter is almost constantly required, and not unfrequently the aid of the engineer. In America, and several parts of Europe, machinery has been extensively introduced to facilitate the labours of the cooper. In 1811, a patent was taken out by Messrs. Flasket and Brown for the following' mode of operating; and as the exclusive privilege granted to those gentlemen is expired, those of our readers who may be so disposed are at liberty to adopt the mechanism employed, which is thus described in Dr. Gregory's Mechanics.

" First, the machinery for cutting the stave consists of a stout bench, having a board or platform annexed to it, capable of being moved endways, to which another board is connected, so arranged as to be moved across steadily by racks and pinions, or screws. The last board has a hollow part made in it, in which the stave-board may be laid, so that one edge of it may project clear beyond the edge of the first-mentioned board; a circular saw is placed either above or below the bench, having its axis at right angles to the line of motion of the first mentioned board, and opposed to the direction of the course of the projecting part of the stave-board; this circular saw is made flat when the straight-edged staves are to be cut, and is dished, or of a spherical shape, when staves with curved edges are wanted. The board first mentioned is moved either in a right line, or is made to assume a curved course, by being confined in its motion by curved grooves, or by curved rods moving against pins; and by the proper management of these sliding-boards, the stave-board is cut by the circular saw of the shape desired.

The machinery next used consists of a large lathe, in which the cask is turned in a vertical position when it is of a large size (after it is formed in the usual manner from the staves prepared as above described), being either fixed in a great chuck placed beneath it, or in a cylindrical cage which surrounds it, fixed upon a strong upright arbor, and revolving between collars, where it serves the office of a mandrill In this lathe the chime and groove for receiving the head are turned in the cask by the application of a proper tool. When the cask is small, the cage is made to turn in a horizontal position instead of revolving vertically. The third operation is to form the head, which is pinioned together as usual, after having the pin-holes made by piercers projecting from the mandrill of a lathe, the distances and depths of which holes are correctly regulated by gauges; it is then turned on a flat revolving table, from which points project to hold it fast, and against which it is held by another revolving piece that is screwed towards the first, where it is brought to the proper size of the cask by fit tools.

The fourth operation is to turn the whole cask at the outside, for which purpose it is placed in a large lathe between two chucks, made to fit into the chines, and attached to the head by points; and then the surface of the cask is turned smooth by a spokeshave, or other fit instrument, held against it by a rest properly placed for the purpose. The patentees bend their wooden hoops for their casks in an expeditious manner, by fastening one end of them to the circumference of a wheel, and pressing them against the wheel as it is turned round; they also describe a method of forming the projecting part in the bung-staves of the small casks called bottles, by flat or concave circular saws, which cut the face of the stave on each side close up to the projection; and lastly, in giving motion to this machinery, the inventors use any of the usual first movers and mill work as may be necessary."

It is due to Mr. George Smart, of Westminster Bridge, to state, that, for some years previous to the date of the patent granted to Messrs. Plasket and Brown, he had in actual operation, on a very extensive scale, a similar arrangement of machinery for making small casks, particularly canteens for the army. The saws and other apparatus were of course more diminutive, but the accuracy of their work may be judged of when it is stated that there was no occasion to plane the edges of the staves to render the bottles water-tight, although submitted to a severe test.