The furs to which the old-time hatter gave preference were the beaver, the muskrat, the nutria, the hare and the rabbit, of which the first was by far the most valuable. These animals all have two kinds of hair on their skins, the innermost of which is short and fine as down, the outermost, thick, long and more sparing, the former being of much use, the latter of no value to the hatter. After receiving the "skins" or "pelts," which are greasy and dirty, they are first cleaned with soap and water, then carried to the "pulling-room," where women are employed in pulling out the coarse outer hairs from the skins, which is done by means of a knife acting against the thumb, the fingers and thumb being guarded by a short leather shield. The skins are then taken and the fur cut or "cropped" from them, which is done by men dexterously using a sharp knife, formed with a round blade, such as is used now-a-days in the kitchen as a "chopping knife." By keeping this knife constantly moving across the skin the fur is taken off or separated without injury to the skin, which is to be tanned for leather or consigned to the glue factory. The cutting of furs, however, had become before 1844 a business in some measure conducted by itself, and a machine had been invented to separate the fur from the skin, which, though it might be considered now a simple affair, was at that time looked upon as a wonder. [Illustration: FUR-CUTTING MACHINE.] We have said the women in the "pulling-room" cut, tear, or pull out the long, coarse hairs from the pelts, and that these hairs are useless to the hatter. But it is impossible completely to separate the coarse from the fine fur by these means, and therefore the fur, when cropped from the pelt, is conveyed to the "blowing-room," finally to effect the separation. The action of the blowing machine is exceedingly beautiful, and may perhaps be understood without a minute detail of its mechanism. A quantity of beaver or any other fur is introduced at one end near a compartment in which a vane or fly is revolving with a velocity of nearly two thousand rotations in a minute. We all know, even from a simple example of a lady's fan, that a body in motion gives rise to a wind or draught, and when the motion is so rapid as is here indicated, the current becomes very powerful. This current of air propels the fur along a hollow trunk to the other end of the machine, and in so doing produces an effect which is as remarkable as valuable. All the coarse and comparatively valueless fur is deposited on a cloth stretched along the trunk, while the more delicate filaments are blown into a receptacle at the other end. Nothing but a very ingenious arrangement of mechanism could produce a separation so complete as is here effected; but the principle of action is not hard to understand. If there were no atmosphere, or if an inclosed place were exhausted of air, a guinea and a feather, however unequal in weight, would fall to the ground with equal