Felt, a kind of stuff, which derives its consistence merely from being fulled or wrought with lees and size, without being either spun or woven. The mechanism of felting is equally simple and curious ; though its theory is little understood, even by professional hatters. - As the surface of hair and wool is by no means smooth, but formed either of plates resembling the scales of fish, or of zones placed over each other, as we find in the structure of horns, it follows that hair or wool, when promiscuously entangled, cannot be easily disengaged, on account of its rough sides, which may be readily perceived, by drawing a hair between the fingers against the root-end. Thus, each inequality of surface accommodates itself to that of another hair, and forms at length a natural texture.

Felt is made either of wool alone, or of a mixture of that article with camel's or other hair, and is used principally in the manufacturing of Hats, to which we refer.