When a hide is lightly limed, it is often easy to remove the long hair, but excessively difficult to get rid of the short under-coat of young hairs, which are found in spring, and which can sometimes only be removed by the dangerous expedient of shaving with a sharp knife. The reason of this difficulty is obvious: not only do the short hairs offer very little hold to the unhairing knife, but, as has been explained in describing the anatomical structure of the skin, their roots are actually deeper seated than those of the old hairs they replace. Several attempts have been made to unhair by machinery, but so far without such success as to lead to their general adoption. The fleshing-machine invented by Garric and Terson, and manufactured in this country by T. Haley and Co., of Bramley (Fig. 27), is furnished with a special wheel for unhairing. An American machine for the purpose, invented by J. W. Macdonald, and said to be capable of unhairing 800 sides a day, is shown in Fig. 28. [Illustration: Fig. 25.] [Illustration: Fig. 26.] [Illustration: Fig. 27.] [Illustration: Fig. 28.] When the hair is very thoroughly loosened, as by sweating, or destroyed, as by sodium sulphide, it is not uncommon to work it off by friction in the stocks; but it is very doubtful whether the saving of labour is not more than compensated by the loss of weight, consequent upon submitting the hide while its gelatin is in a partially dissolved condition, to such rough usage. [Illustration: Fig. 29.] After unhairing, the loose flesh and fat are removed from the inner side of the hide by a sharp-edged knife E (Fig. 26), partly by brushing or scraping, partly by paring. It is necessary not only to cut off the visible adhering fat, but to work the hide well, so as to force out that contained in the loose areolar tissue, which would not only impede tanning, but is liable to soak completely through the hide, producing most unsightly blotches. Several machines have been introduced to supersede hand-fleshing, but with only partial success. One of the best is Garric and Terson's machine (Fig. 27), which gives a very level flesh, free from galls, and without so much loss of weight, but scarcely so clean as desirable, while the saving in labour is not great. Molinier's machine (Fig. 29), and that of Jones and Rocke, are well adapted for skins, but hardly capable of fleshing an entire hide. All these machines are very similar in principle, the working parts consisting of drums with oblique or spiral knives.