84 LEATHER 



the grain-side of the leather; after carefully compressing every part in this way, the 

 butt is laid upon a flat bed of solid wood-work, prepared for the purpose, and the brass 

 roller is worked backward and forward until every portion is sufficiently compressed 



1361 



(fig. 1363). The roller a is a cylinder varying from 9 to 12 inches in length, and from 

 7 to 10 inches in diameter ; b is an open box over the roller, into which weights are 

 placed to make the necessary pressure, ten or twelve cwts. being frequently used for 

 the purpose ; c, c, forms a fulcrum for lifting the roller from the bed to the leather ; 

 d is the handle by which the machine is worked. When the compression is com- 

 pleted, the only thing remaining to be done is properly to dry the leather, and then it 

 is fit for the market. 



Some manufacturers place on the bottom of the tan-pit five or six inches of spent 

 bark, and two or three inches of fresh bark over it, then, a hide, and so alternately 

 bark and a hide, until the pit is nearly full, reserving a small space at the top for a 

 thicker layer of bark, over which weighted boards are laid, to condense the whole 

 down into the tanning infusion. 



The operation of tanning sole leather by the above method occupies a year or more, 

 the time depending on the nature and stoutness of the hide. 



A perfect leather is recognised by its section, which should have a glistening 

 marbled appearance, without any white streak in the middle. 



Crop hides are manufactured very much like butts, that is to say, they are placed 

 in milk of lime until the hair is sufficiently loosened, equality of action being secured 

 by occasionally moving them in the menstruum ; they are then cleared of the hair and 

 other impurities by the fleshing knife, worked on the convex beam already described, 

 they are then freed from lime by thorough washing. The next process is to plunge 

 them into a weak ooze, from which they are transferred to other pits with stronger 

 ooze ; all the while they are frequently handled, that is, moved up and down in the 

 infusion. After a month or six weeks they are subjected to a mixture of ground oak- 

 bark and stronger ooze in other pits, to a series of which they are progressively sub- 

 jected during two or three months. 



The hides are next put into large vats called layers, in which they are smoothly 

 stratified, with more bark and a stronger infusion. After about six weeks they are 

 taken out of these vats, and subjected to a new charge of this material, and allowed 

 to lay some two months ; this process is repeated once or twice more till the hides 

 are thoroughly tanned. They are then slowly dried in the shed, and folded for 

 market. Although in general the stoutest and most compact hides are used as sole 

 leather (notwithstanding that they have not been condensed by the tanner, as in the 

 case of butts), yet many are appropriated to other purposes by the currier, and the 

 lighter cow-hides are manufactured for the upper leather of stout shoes, water- 

 boots, &c. 



The process of tanning skins (as calves, seals, &c.) next claims attention. These 

 are placed in the lime-pits until the hair can be easily removed, a process which 

 requires about ten or twelve days ; this being accomplished, they are next washed in 

 water, so as completely to remove the lime, as far as washing can secure its removal, 

 and then immersed in a lixivium of pigeon's dung, dog's dung, or matters of a like 

 nature ; in this state they remain about ten or twelve days, the state of the atmo- 

 sphere rendering the process quicker at one time than another ; here also they are 



