I 3 4 THE PRINCIPAL SPECIES OF WOOD. 



Blue Gum, Fever Tree. Eucalyptus globulus. 



Nomenclature. 



Blue Gum (local and common Fever Tree (Australia). 

 name ). Balluck (Australia). 



Locality. 



Native of Australia acclimated in southern California and else- 

 where throughout the world. 



Features of Tree. 



Two hundred to sometimes three hundred or more feet in height. 

 Three to six feet in diameter. Loose, shaggy, exfoliating 

 bark.* Leaves sometimes twelve inches in length. Color 

 varies with age. Characteristic odor. 



Color, Appearance, or Grain of Wood. 



Straw color. Sapwood lighter. Indistinct annual rings. Fibres 



interlaced so that it is hard to work, particularly when dry. 

 Structural Qualities of Wood. 



Hard, heavy, durable, difficult to split, particularly when dry. 

 For this reason trees are sawn into planks, if at all, as soon as 

 they have been felled. The green wood works much more 

 easily than the dry. Blue Gum is less elastic although it com- 

 pares with ash and hickory. 

 Representative Uses of Wood. 



Rollers, paving-blocks, ship -build ing, fuel, carriage-making. 

 Small pieces boiled in water and then in linseed oil are used 

 for insulator pins on telegraph poles, piles and mine timbers in 

 California. A principal fuel in Southern California. 

 Weight of Seasoned Wood in Pounds per Cubic Foot. 

 43 to 69 (Mueller) 

 57 to 69 (Lazlett). 

 Modulus of Elasticity. 

 Modulus of Rupture. 

 Remarks. 



The Eucalyptus of California. The species planted in malarial 

 districts. Sanitary powers due to evaporation from large leaves 

 or presence of essential oils, which are thought to have medicinal 

 qualities. Grows very rapidly. 



* The bark is variable. Some trees of nearly i foot diameter have smooth green 

 bark resembling that on young willow saplings; most others have the shaggy bark, 

 while from some this has dropped away, exposing a smooth grayish interior sug- 

 gesting that of the sycamore. Planted more widely than other Eucalypts. The 

 species used in malarial districts. The " Eucalyptus" of California; one of the 

 fastest growing trees in the world. Trees eight or ten years old, will, if cut down, 

 produce shoots seventy five to one hundred feet high in six or eight years, and 

 cuttings may be continued indefinitely. The common name Blue Gum is applied 

 to eleven other distinct species, so that the botanical name should never be 

 omitted. Globulus refers to the globular seed cases. 



