94 TIMBER 



There is no doubt that close grain, durability, and power of 

 abrasion, the qualities necessary for good paving blocks, are 

 to be found in the red gum if only the timber can be so 

 seasoned as to prevent warping and twisting. In some 

 tests made by Mr. W. Kendrick Hatt, Ph.D., of the United 

 States Forest Service, joists of 16 ft. span, 4 inches by 8 

 inches to 6 inches by 8 inches, gave an average fibre stress 

 at elastic limit of 2,608 Ibs., a modulus of rupture of 4,570 

 Ibs., and a modulus of elasticity of 1,075,000 Ibs. per square 

 inch ; the average crushing strength parallel to grain was 

 2,620 Ibs. and at right angles to grain 639 Ibs. per square 

 inch. 



Tupeloe Gum or Tupeloe (Nyssa aquatica), another of the 

 three important gums of the southern United States, is found 

 over the same district as the red gum, but the chief district 

 from which the supplies come is near Mobile and Southern 

 and Central Louisiana, where the country is very swampy 

 and where the tree during the rainy season stands in from 

 6 to 20 ft. of water. 



The heartwood varies in colour from a dull grey to a 

 dull brown, the sap, which is considerable, is white or 

 light yellow, like that of poplar, and after seasoning it is 

 difficult to distinguish the better grades of the sapwood from 

 poplar. It is sold in the American market as bay poplar, 

 as it was substituted for a grade of yellow poplar found 

 near Baltimore which is now getting scarce. In the 

 furniture trade it is sometimes called Circassian walnut, 

 and some manufacturers call the wood nyssa, a subterfuge 

 again, owing to the feeling against these gums. Tupeloe 

 is about the same weight and strength as red gum, but 

 much tougher, and there is the same difficulty in seasoning, 

 so it is cut into boards of one inch thick or less. It is 

 used for furniture drawers and backs, for panel work and 



