504 15 A UK. 



n. Measures for Bark. 



In selling bark-coppice by area, it is important to know how to 

 estimate the quantity of bark which has l)C'cn harvested. This 

 may be done by measuring its rough volume ; by weight ; or 

 indirectly, by measuring the volume of the barked wood, from 

 which the yield of bark may be determined by means of experi- 

 mental ratios. 



Measurement by rough volume is done by the bale. Although 

 this method has the advantage, that the bark can be removed as 

 soon as it is sufficiently dry, and there is thus little danger of any 

 loss of tannin, yet it affords for both purchaser and seller such 

 an uncertain measure of the yield, that it is employed only to a 

 limited extent. If measurements are to be made by bales, not 

 only must the length and girth of the bales be nearly uniform, 

 but the hark must also be uniformly packed in each bale. 



The best, and at present, the most usual sale-measurement is 

 the weight. As soon as the bark is dry, it is packed in bales 

 and weighed in the forest by means of a steel-yard or spring- 

 balance. Everything then depends on the degree of dryness of the 

 bark, for green bark must lose 40 — 50% of water to become air- 

 dried. In the interest of the purchaser, however, the bark must 

 not be kept a day longer in the forest than is necessary, owing 

 to the danger of a loss of tannin. Although one might anticipate 

 disputes between seller and purchaser as to the proper date for 

 measuring bark, yet experience proves that this seldom happens, 

 A prudent tanner will allow the bark to remain in the forest no 

 longer than is absolutely necessary ; he knows that it is more 

 to his interest to pay for the bark when soniewliat moist than 

 to risk its being badly washed by the rain. 



The third mode of measuring bark consists in merely measur- 

 ing the peeled wood, and assuming that its volume will bear a 

 fixed ratio to that of the bark which has been harvested. This 

 custom is always followed in Franconia. It cannot be denied 

 that this method has certain advantages, as it saves labour and 

 avoids inconvenience, but to it is attached the great disadvantage 

 that the ratio between wood and bark varies every season, and 

 neither purchaser nor seller can be certain how much bark has 

 been bought or sold. It may be suggested that an average 



