THE TIMBERS OF COMMERCE 



No. 28. CAOBA. (Possibly Swietenia Mahagoni. 



Jacq.) 

 Plate III. Fig. 21. 



Natural Order. Meliacese. 



Source of Supply. Mexico. 



Alternative Name. Bois d' Acajou a Meubles. 



Physical Characters, etc. Dry-weight 67 lbs. per cu. ft. 

 Hardness Grade 3, compare Blackthorn. Smell and taste 

 none. Burns indifferently : embers glow in still air : some 

 juice expelled by heat. Solution the colour of the wood. Splits 

 easily but irregularly. 



Grain. Moderately fine and even. Surface smooth and some- 

 what lustrous. 



Bark. ? 



Authority. Kew (55). 



Colour. Red with dark bands and fine black lines (the pores) : 

 darkens on exposure. Sap-wood brown. 



Anatomical characters. Transverse section: — 



Pores. Readily visible on account of their black and white 

 contents, size 2-3, moderate sized, uniform : thinly and irregu- 

 larly scattered : many radially sub-divided, usually single but 

 many pairs and threes, rarely many in a group : also often pairs 

 divided by a ray : 1-16 per mm. : sometimes green contents 

 as well as white and black. 



Rays. Scarcely visible, size 5, uniform : equidistant : long, 

 narrow, tapering at length : 5-7 per mm. : deep crimson : very 

 sinuous in longish waves but scarcely avoiding the pores. 



Rings. Fairly clear if indicated by the light-coloured lines. 



Soft-tissue. In often-readily-visible continuous, numerouss 

 concentric lines of regular contour, rather broader than the 

 rays. They occur at irregular intervals sometimes hardly the 

 diameter of a pore apart. Also narrowly encircling the pores 

 (micro.). 



Pith. Round, very coarse -celled, about ij mm. wide. 



Radial Section. Pores very prominent, dark red or black line, 

 the chief features of the wood : also an occasional white one. 



Rays. Just visible, fine, red flakes. 



Rings. Vague. 



Soft-tissue. Just traceable as extremely fine lines. 



Type specimen received from the Royal Gardens, Kew, being 

 one of the series of Mexican Woods exhibited at the Paris 

 Exhibition of 1900 by the Mexican Government The specimen 

 was marked : " Caoba : Nombre scientifico, Swietenia Maha- 

 goni." 



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