146 TANNIXa MATERIALS. 



these dry materials remain unconsnined. The only protection agpinst 

 forest fires appears to be constant vigilance and stringent regulations 

 faithfully enforced. 



Another source of damage consists in the liability of large trees to 

 be thrown down by the winds when open clearings are made exposing 

 the standing timber. 



It is a matter of common experience that extensive areas once covered 

 ■with a heavy growth of hemlock, as, for example, in Greene and Ulster 

 Counties, New York, have, within a period comparatively recent, been 

 ■wholly or nearly exhausted of their tanning materials,^ and that exten- 

 sive tanneries in many ])laces have been wholly abandoned, their 

 owners, if continuing the business, being compelled to seek new locali- 

 ties. Under the best manipulation, a cord of good hemlock bark will 

 make about 200 pounds of sole-leather.^ 



Various substitutes for hemlock and oak barks have been tried with 

 some degree of success.^ 



CULTIVATION OF OAK COPPICE FOR TANNING MATERIAL. 



From present indications it seems probable, that our future reliance 

 must be placed upon the cultivation of oak coppice. It will therefore 

 be of interest to notice some of the principles concerned in the produc- 

 tion and preparation of this material in other countries. 



It appears from official reports, that in countries where great atten- 

 tion is paid to the development of forest resources, the production of 

 oak bark is steadily increasing, and that its price is advancing, having 



i Where lands are allowed to lie after the hemlock timber is cnt off in this repiou, 

 the succeeding growth is chestnut, oak, birch, betch, or poplar, but never hemlock. 



^A calculation based upon the returns of 12 large hemlock tole-leather tanneries in 

 Pennsylvania, using 64,316 cords of bnrk, and makijig 10.727,.528 pounds, shows the 

 average to be 166 pounds of leather to a cord of bark. The highest yield was 200 

 pounds in the tanneries ; the lowest 122 pounds. 



Returns from 12 oak sole-leather tarneries gave from 15,947 cords 2,520,919 pounds, 

 ■or an average of 1.59. The largest yield was 231 pounds ; the least, 126. 



Two tanneries making oak harness-leather showed a yield of 292 and 294 pounds to 

 the cord. In buying hemlock bark, a cord is reckoned equal to a ton, and the practice 

 of weighing instead of measuring bark is apparently on the increase. 



At a Hide and Leather Convention held in New York City in October, 1877, resolutions 

 ■were passed recommending the purchase of hemlock bark by the ton of 2,000 pounds, 

 in.stead of by measure, as iireferable throughout the whole country. 



It is estimated that the French tanneries employ 300,000,000^ kilograms (330,690 

 tons) of bark annually. The exportation of ground bark somewhat exceeds the im- 

 portation. (Nanqnette.) The bark from a sthre of oak coppice of thrifty growth will 

 make 30 kilograms of dry bark. Trees of two revolutions (modernes) give per stere, 

 40 kilograms. 



Taking a general average of the hemlock forests of Northern New York, the yield 

 of bark may be estimated at oi^ cords to the acre. Under the most favorable circum- 

 stances, it may come up to 10 cords. Much waste has occurred, and is now going on, 

 in this region, the price of hemlock lumber being so low that much of it is left to rot 

 on the ground. Of course no provision whatever is made for reproduction, or for dis- 

 posing of the rubbish by careful burning, and the decaying timber remains, the breed- 

 ing place of injurious insects and the aliment of running fires, the waste from wliicu 

 has been very great. The longest estimates fix the period of exliaustion, within reach 

 of existing tanneries in Lewis County, at fifteen years. At an extensive manufactory 

 of tanning extract in that county, the yield is about 400 pounds to the cord. 



3 The bark of the red pine (Finus contorta, Dongl.) has been used to a limited extent 

 at Salt Lake City, Utah, as a tanning agent, the price j)aid being from §12 to §40 per 

 cord. It is estimated bj" a practical tanner that it has abont two-thirds the value of 

 hemlock bark. The supply is scanty, and wholly derived from the canons of the 

 Wahsatch Mountains, where the wood of this species is obtained for lumber. 



The Polygonum ampltibium (water smart-weed), growing wild in abundance, has been 

 used to some extent. in Isebraska, and the extract is prepared in Iowa. The sweet fern 

 and some other plants have been used. 



