812 



AMERICAN FORESTRY 



beetle. The hinged hooks are so accurately adjusted that 

 the wearer of the arm can use them in picking up a 

 glass of water and drinking from it. When the hooks 

 are not in use they may be concealed by slipping a hollow 

 hand over them. This and other devices emphasize the 

 skill, patience, and ingenui- 

 ty of manufacturers in pro- 

 ducing limbs as nearly as 

 possible like the natural 

 members. 



Some controversy has 

 arisen as to the origin of 

 the word "cork" as applied 

 to a limb. Most people are 

 under the impression that 

 the name implies that such 

 limbs are made of cork, or 

 that they are as light as 

 cork. The latter meaning 

 is reasonable, but the as- 

 sumption that limbs are 

 now made, or ever were 

 made, of cork has no basis 

 in fact. Cork is nothing 

 more or less than the bark 

 of a species of oak tree that 

 grows in southwestern Eu- 

 rope and in northwestern 

 Africa (Quercus ilex). It 

 is too weak for use as arti- 

 ficial limbs, and if it were 

 otherwise fit, it could not 

 be had in pieces of suffici- 

 ent size. The name of the 



limbs is said to have originated in a quite natural way, 

 and refers to the town of Cork in Ireland where once 

 they made artificial limbs of excellent quality. The 

 town gave its name to the product. 



In the manufacture of such limbs different materials 

 are employed, rubber, leather, steel, felt, and wood, and 



the most important of these is wood. More than one 

 wood is serviceable, but there is one which is usually 

 rated far superior to all the others, and it holds undis- 

 puted first place in the industry, though the government's 

 published statistics apparently prove the contrary. These 



statistics fail to make it 

 clear that some of the 

 woods shown in the figures 

 are for crutches rather than 

 for limbs proper. White or 

 English willow (Salix alba) 

 is the wood par excellence 

 for manufactured limbs. It 

 is frequently listed as red 

 willow, but that is not 

 strictly correct, for red wil- 

 low is a different species, 

 a native of this country, 

 while white willow is for- 

 eign, though it has been 

 so widely planted in the 

 United States that it is 

 plentiful in many regions. 

 White willow is essen- 

 tially a town and highway 

 tree. It occurs in parks, in 

 yards, on street borders, 

 and along highways where 

 it casts delightful shade and 

 forms a pleasing feature of 

 the summer landscape. Be- 

 ing an open-ground tree, 

 and usually not much 

 crowded, it develops a 

 short trunk and an enor- 

 mous crown. The tree seldom furnishes more than one 

 short sawlog, and the logs range in diameter from one 

 to two and a half feet. Old trees may be three feet in 

 diameter, and in extreme cases six feet. The larger the 

 tree the better the wood for artificial limbs. 



Thus it is that the supply of wood for artificial limbs 



PROGRESSIVE STAGE IN LIMB MANUFACTURE 



The blocks of willow wood have been roughly shaped and mounted in 

 order to adjust the proportions preparatory to the final cutting and the 

 finishing touches. Much of the work cannot be done by machinery, but 

 must be perfected with carving tools used by hand. This photograph was 

 obtained through the courtesy of Pomeroy Company, New York. 



WOODEN FOOT IN ACTION AND AT REST 



This illustration gives an idea of the articulation of the wooden foot and its 

 action during the process of walking and standing still. The inventors have de- 

 voted their best thoughts to the perfection of an ankle joint which will not only act 

 naturally, but will endure the severe strains to which it is subjected. 



