Very little of this is done at present in the United States. After the bare body of the hat is stiffened, if a flowing nap of beaver, otter, neutra, or other fine fur is desired, finer than that of which the body is made, half an ounce more or less of the superior uncarroted stuff is weighed out, sufficient to cover the whole outside surface of the hat. The hatter lays this precious morsel with perhaps one-eighth ounce of cotton on the hurdle, under the bow, as he did with the stuff for the body, and with a similar but lighter instrument, these two stuffs are completely mixed and spread upon the boards, as evenly as his experienced hands can do it; the cotton being used merely to enable him to handle the fur, which otherwise would be so thinly spread, and so attenuated of itself, as to endanger the simple act of lifting it. This mixture of fur and cotton is next spread upon the wet bare body of the hat as it lies upon the plank at the kettle, a little water is sprinkled over it and beat down with a brush. The hat with this surface covering is wrapped very carefully in a piece of cloth or coarse hair-cloth, and operated on very lightly, and nearly in the same manner as when felting the body. The object to be attained is to get the fibres of the fine fur to penetrate the body, and take root as it were therein--great care and watchfulness being demanded of the workman at every motion of his hands, in this manner of working. The points of the fibres of the beaver fur penetrate the body of the hat, and having once got a footing, it constantly advances, as the active careful rolling, folding and unfolding, shaking and tossing go on, until the fur has separated itself from the cotton; by its boring, having obtained a firm lodgment in the solid felt of the hat body root end foremost. The cotton with which it was mixed is left behind loose and useless, for want of the little rough scaly property that the other possessed. An inexperienced workman in thus ruffing a hat is liable to continue his work too long, until the beaver napping has burrowed quite through to the inside of the hat, where it is lost.[C] In the various operations of the hatter with hot water, whether in body-making, napping, or dyeing, &c., the water should not be allowed to boil, for independent of the damage to some kinds of stiffening, as hair contains a large portion of gelatine in its substance (to which alone it owes its suppleness and toughness), this gelatine will be separated from the hair. This is particularly the case with napped hats, for when thus treated the fibre becomes much more brittle than before, and the nap soon breaks off round the square. Fur hats having a flowing nap are sometimes clipped very short with revolving shears similar to those used in dressing cloth, and which is done previous to blocking or dyeing. [Illustration: Fig. 5. Hat Block.] Blocking.