_Harness Backs._--About a hundredweight of hen manure is put into a suitable tub or vat capable of holding about fifty gallons; some thirty gallons of water, at a temperature of about 100° F., is poured on to the manure, and the whole is thoroughly stirred up by means of a wooden stick or plunger, working the manure about in order to mix it to a consistence of thin soup. The vat is now stored in a warm place, so that the temperature is kept about 70° F.--it is customary to store this in the boiler-house, or some similar warm room. It should be stirred two or three times a day, until it begins to show signs of working; two days is generally sufficient for this. A pit is now prepared, with the necessary amount of water; and, by the aid of a steam pipe, or other similar means, the temperature of the water is raised to 70°, and the contents of the bate tub are now added. This should be poured into the pit through a sack, or a canvas filter, so as to keep back stones, solids, feathers, and other extraneous matters. The pit is now thoroughly plunged, and the goods entered; these should be handled up three to four times a day for two days. At the end of two days the goods are usually scudded, by working the back on an ordinary unhairing beam with an unhairing knife. They then go into a fresh pit containing a new solution of bate made up in the same manner, and, when sufficiently bated, which generally takes about three days, the goods are removed from the pit, scudded again by working them over with a slate scudding tool, when they are ready for tanning. Some tanners give them a bath of boracic acid prior to their going into the tanning liquor; this has the effect of materially brightening the colour. The second pack of harness backs go into the same liquor--which must be re-warmed to a temperature of 70°--in which they are handled as before for about two days, and are finished off in a new liquor made as above described. It will be understood, therefore, that in a tanyard, working regularly, the pack of backs go first into an old bate for two days, and are then finished off in a freshly made one; so that each pack gets two days in an old pit, and one or more days in the new. The bate in the tub may also have a second water, or be strengthened. _Dressing Hides._--For these goods a somewhat stronger bating effect is required, and pigeon manure is therefore frequently used. The preparation of the bating liquor is as described above, both as regards quantity and temperature of the water and time of maceration.