THE TIMBERS OF COMMERCE 



No. 98. JARRAH. Eucalyptus marginata. Sm. 

 PLATE VIII. FIG. 65. 



Natural Order. Myrtaceae. 



Synonyms. E. floribunda. Hueg. E. Mahagoni. F. v. M. 

 E. hypoleuca. Schau. 



Alternative Names. Mahogany Gum. Australian Mahogany. 

 Yarrow- tree (42). Curly Jarrah, in Victoria (46). 



Sources of Supply. Western Australia, New Zealand, Victoria. 



Physical Characters, etc. Dry weight, 50^-64 Ibs. per cu. ft. 

 Hardness Grade 2, compare Boxwood. Smell or taste none. 

 Burns indifferently, embers soon die out and leave the carbonized 

 wood. Heat expels drops of resin or gum. Ash black. " One 

 of the least inflammable woods " (42). Solution with water or 

 alcohol brownish. Commercial form, chiefly paving blocks or 

 planks from which they are cut. 



Grain. Course, open sinuous. Surface rather dull. The 

 ground tissue the brightest portion, the pores and rays very dull. 



Bark. Deeply fissured, dark grey or brownish, fibrous, per- 

 sistent, J-f inch thick, of two layers, the outer fibrous, the inner 

 compact : grey. 



Uses, etc. " Good for paving, piles, sleepers, ship-building and 

 for purposes where it is exposed to the attacks of the teredo, 

 chelura or white ants." Durable under all circumstances 

 properly seasoned. Liable to be unsound in the heart and to 

 contain "gum- veins" or cavities. Becomes harder with age. 

 " It appears imperishable, excellent qualities for paving : apt to 

 warp if not well selected " (28). 



Authorities. J. Ednie-Brown (21), p. 10. Laslett (4), p. 231. 

 Petsch (28), p. 125. F. von Mueller (42), p. 3. Lefroy (59), 

 Miller's (20). 



Anatomical Characters. Transverse section : 



Colour. Very dark chocolate or the colour of dried blood with 

 black zones here and there : runs lighter in colour at times. 

 Sap-wood brownish, ecru : to f inch wide, well defined from 

 the heart. 



Pores. Clear in certain lights in dark pieces, clearer in 

 light wood, not prominent on account of the lack of contrast 

 of colour. Size, i or 1-2, with considerable variation in each 

 ring in no particular order : irregularly distributed, often 

 running in oblique, straggling lines which occasionally reverse 

 their direction : mostly single, but joining up into compact 

 strings of about 15 pores : numerous, 0-15 per sq. mm. : 

 round or oval : often contain resin or gum. Radial sec., pro- 

 minent, coarse, open grooves usually filled with dark contents : 

 often reversed in adjoining bands. In tang, sec., usually 

 sinuous. 



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