484 



AMERICAN FORESTRY 



another. Beauty and utility are often wide apat^ in their 

 demands. 



Along with the distortion of the structure in the wood 

 of a crotch there is usually a very pronounced deepening 

 of the color due to excess deposits of pigments and infil- 

 trates. This shows in marked contrast to the adjacent 

 wood and adds greatly to the decorative quality. A long 

 narrow crotch may give the effect of a fountain or tufts 

 of beautiful plumes. 



Often the wood of crotches is defective and where the 

 branches grow too closely together there is danger of the 

 bark being caught and covered by later growth. This 

 is what dealers in logs call "in-barking", a general term 

 applying to all cases where bark is caught in the wood, 

 as in healed-over wounds and fluted trunks. 



HEART BREAK IN WOODS 



It is not at all unusual to find in certain woods that 

 cross-breaks have occurred in the heart of the logs. This 

 defect is very comniion in African mahogany and during 

 the war the writer saw hundreds of boards, otherwise 

 perfect, culled because of these breaks. They vary in 

 length or depth from a few inches to a foot or more, and 

 there may be several of them close together. They are 

 variously referred to as heart breaks, cross breaks and 

 compression failures. 



A CROSS, OR HE.'KRTBREAK 

 Heartbreak or compression failure in a piece of mahogany. 



The cause of this damage has never been positively de- 

 termined. Some believe that it occurs in the standing tree 

 as the result of heavy wind storms. Others are of the 

 opinion that the breakage results when the tree crashes 

 to the ground when felled for lumber. The latter cite 

 the fact that the breaks are usually fresh looking and 

 show no pronounced discoloration or deposits such as 

 one would expect to find in old injuries, particularly 

 in a wood that contains as much gum as mahogany does. 



Whatever the cause the defect is very serious and may 

 be overlooked until the later stages of manufacture. The 

 writer has a section of an airplane wing beam of Sitka 



spruce which shows two of these breaks. In the case of 

 mahogany a break which is scarcely noticeable in the 

 lumber before it is finished will show up badly when 

 filler and stain are applied. 



These breaks are the sign of rather soft and brash 

 wood and it seems the trees in which they are found 

 are always large. Some of the old Sitka spruces which 

 produced clear light-weight lumber were found to be un- 

 fitted for airplane construction because their wood was 

 lacking in the essential toughness and resilience. 



ASH-SPLINT PACK BASKETS 



The most serviceable pack baskets used in the North 

 Woods are made by the woodsmen during their spare 

 time. They weave them from splints from a slow-grow- 

 ing ash tree. 



The basket-maker selects a straight clear-boled brown 

 ash tree growing in the forest, fells it and peels off the 

 bark. Any season of the year will do, but the bark peels 

 easiest in late spring or early summer. 



The wood of the ash-tree is made up of alternating 

 layers of soft porous material of the spring growth and 

 tough fibrous material of the summer growth. By ham- 

 mering hard all over the peeled log the layers can be sep- 

 arated. So the woodsman proceeds to pound the trunk 

 with the back of his ax until the growth layers loosen up. 

 A single hammering will loosen from two or three to as 

 many as ten layers, depending upon the vigor of the 

 blows. After all the loosened layers are removed the pro- 

 cess can be repeated. 



The layers are torn off in long narrow strips about 

 three-quarters of an inch wide and rolled up tightly. In 

 this form they can be stored indefinitely. All that is 

 necessary to render them pliable and fit for weaving is 

 to soak them in cold water for an hour or so. They will 

 then become very pliable and withstand almost any 

 amount of bending and twisting without cracking or 

 breaking. In fact before wire came into use for the pur- 

 pose it was common practice in some parts of the country 

 to use ash splints for tying hay bales. 



UNTREATED SPOTS ON PILING 



Users of creosoted piling have occasionally been great- 

 ly puzzled on observing shipworms boring through heav- 

 ily creosoted wood. Experiments with sheathing creo- 

 soted timbers with untreated planks have demonstrated 

 that if the microscopic larva can get a start in the un- 

 treated wood the worm which develops becomes resis- 

 tant to creosote poison and can bore into the heavily 

 impregnated wood. If there are any spots left untreated 

 on piling and wharf timbers they will permit the young 

 shipworms to obtain a foothold and eventually destroy 

 the whole timber. 



