Barrel, a hollow vessel made of staves, set on end, arranged around a circle, and bound together with hoops. By each stave being made wider in the middle and tapering a little toward the ends, the barrel is of larger diameter, or bulges, in the middle. The bevelled edges of the staves cause them to fit closely together, making a tight joint along their length. The ends are closed by circular heads, the edges of which are made thin to fit into a groove cut to receive them near the ends of the staves, in which they are held fast by driving the hoops upon the swell of the barrel. The construction of the barrel is most ingeniously adapted for combining great strength with lightness. It resists pressure from without by the arched arrangement of the staves; and the hoops secure it from the expansive force of gases often generated in its contents. Its form is the most convenient for transportation, admitting of the vessel being rolled or rapidly swung by hooks placed under the chine or ends of the staves. It is not strange, therefore, that many millions of them should be annually made for the numerous uses they serve. In the form of kegs, firkins, liquor casks, butts, hogsheads, etc, they are met with everywhere.

Yet the Chinese, with all their ingenuity, it is said, have never made a barrel. - Until recently barrels have been constructed entirely by hand, the cooper shaving the. staves with the draw knife, and shaping them by clamps. But machines are now applied to this purpose, by which the work is done much more expeditiously. The staves are planed, steamed, and then passed between a series of rollers, which compress and bend them into proper shape. A stave is next set up on end in a frame, which holds it securely and forces it to its right bend, and swinging around to a plane working vertically on one side, one edge is jointed to its right bevel, and swinging to the other side, the opposite edge is served in the same way, the grooving at each end or crozing, the chamfering of the ends, and sawing off, all being done by different cutters at the same time. Other machines saw the staves, and some cut them with great rapidity directly from the block; but these are for making what are called slack barrels, which do not need to be so perfectly tight and strong as those used to contain most liquids. - As a measure of capacity the barrel is of very variable dimensions, differing in size in the different states, and with the material it is designed to hold.

The measure of capacity called barrel bulk is 5 cubic feet. The old English measures were 31 1/2 gallons for a barrel of wine, 32 for ale, and J 36 for beer; but by a statute of 1 William and Mary the beer and ale barrel was equalized to 34 gallons. This, however, only created confusion. The dimensions of the barrel in England are as follows;

Gallons.

Cubic inches.

Wine barrel.....

81 1/2

7,316 1/2

Ale barrel (London).....

82

9,024

Ale and beer barrel (England)......

84

9,518

Beer barrel (London)......

86

10.152

In the United States the barrel for wine, beer, and eider is 31 1/2 gallons. The lamp-oil barrel of Cincinnati contains 43 gallons. The whiskey barrel usually contains from 40 to 45 gallons. In Maryland, a barrel of corn is equal to 5 bushels; a barrel of fish, 220 lbs.; a barrel of flour, 196 lbs.; and of lime, 320 lbs.