HAT, a covering for the head, which is generally made of a mixture of Spanish wool with that of hares, kids, rabbits, beaver, &c. Lately, leathers have been usefully employed in the manufacture of this article.

As it would be too tedious to detail the various processes the different materials undergo, before they are converted into felt, we shall content ourselves with observing, that the degree of fineness depends entirely on the greater or less quantity of hare's wool and beaver employed in its texture. The former is usually mixed with equal portions of the finest sheep or lambs' wool; but the beaver is generally confined to the facing of finer hats, into which it is worked superficially, and therefore seldom used for the body, or principal material of this article.

After the hat has been shaped and fashioned, it is dyed in a liquid prepared of logwood, and a mixture of green copperas and blue vitriol; when it is stiffened with common glue: the beer grounds (which are previously applied to the inside, to prevent the glue from penetrating through to the face) being perfectly dry. In the dyeing process, however, our hatters acknowledge their inferiority to those of France and Holland, which is imputed to the water on the Continent being kept for many months, nay, in some places, for years, before it is used.—Various other little operations are still required, in order to soften and give the hat its final shape, after which it is lined and trimmed for sale.

A patent was granted in January 1782, to Mr. Robert Golding, of Southwark, hat-dyer; for his method of dyeing, staining, and colouring beaver hats green, or any other colour.—The inventor directs the nap of the hat to be raised by means of a card, on the side intended to be dyed, and then boiled in alum and argol. A thin paste should be made of flour, or clay, which is spread over every part that is not to be dyed, and then closed; or the hat may be previously pasted, and instead of being boiled, it should be only simmered in the same liquor. As soon as the paste is spread, plates of copper or other metal, shaped like a common funnel, are fixed over the paste, to prevent the dye from penetrating through. In this state, the hat is immersed in the dye, till the colour be sufficiently fixed; when it is taken out, opened, and cleansed from the paste: but, if any colouring particles have penetrated through the felt, they may be removed by rubbing them with a small quantity of spirit of salt, aqua fortis, &c. The compounds employed in dyeing, are fustic, turmeric, ebony, saffron, alum, argol, indigo, and vitriol, with urine, or pearl-ash, at the option of the dyer; all of which are used together, or separately, according to the colour required.

Among the different patents granted to hatters, for discovering new materials in this manufacture, such as that of Mr. J. Burn, in 1792, for mole-fur; and another to Mr. J. Tilstone, in l794, for kid-hair; we shall only notice an invention of Mr. George Dunnage, who, in November 1794, obtained a patent for his Water-proof Hats, in imitation of beaver.

The articles he employs are similar to those commonly used for the making of hats, with which he mixes Bergam, Piedmont, or Organzine silk. These are dressed and worked in a peculiar manner; though we understand that hats thus prepared become heavy and oppressive to the wearer, while they acquire an ugly colour.—The curious reader will find the patentee's specification inserted, at full length, in the 4th vol. of the Repertory of Arts and Manufactures. The same manufacturer procured another patent in November 1798, for a method of ventilating the crowns of hats. This invention consists in separating the top from the sides of the crown, so that the tip, or top-crown, may be either raised or let down at pleasure, in order to admit the external air, or to exclude it from circulating in the crown of the hat. The whole contrivance is effected by means of springs, sliders, sockets, grooves, loops, and cases, which are connected with the top and side-crown: thus the admission or exclusion of atmospheric air in front, behind, or on either side, may be regulated accordingly.—As this invention is ingenious, we refer the reader to the 10th vol. of the work last quoted, where he will find a minute account, illustrated by an engraving.