The wood is superior to Y/hite Oak in all mechanical properties. It is 

 characterized hj moderate shrinkage and excellent weathering qualities. 

 Heartwood of Mora Amarilla has long been recognized for its high degree of 

 resistance to decay and insect attack. It is not resistant to marine borers, 

 hov/ever. 



Mora Amarilla is prized locally in the tropics for heav^/ durable construction. 

 It is frequently used for oiles, poles, foundation and bridge ti.ibers, 

 culverts, crossties. 



3. Brazilian Louro (Aniba Duckei , A. cf. riparia, O cotea sp,). In the 

 Amazon region of Brazil there are a number of species knovm as Louro. The 

 above-named species represent three of these. They are similar in appear- 

 ance and almost identical in physical and mechanical properties. These 

 three species are therefore grouped for the purpose of discussion. The 

 Brazilian Louros, based on descriptions of the trees from which test mater- 

 ial was obtained, attain diameters of about 2 feet and heights of 100 feet 

 or more with a clear bole extending about two-third of total height. Little 

 information is available concerning their abundance although, together with 

 closely related species of the Laur'aceae, they constitute a significant 

 part of the forest. 



The wood of the Brazilian Louros is comparable to Wnxte Oak in density, 

 but is considerably stronger and stiff er than Oak. Only in com.pression 

 across the grain, are they approximately equal to White Oak, Shrinkage 

 is less than that of Oak, and resistance to checking and splitting upon 

 exposure to weathering is very high. The timbers of the group are extremely 

 resistant to decay. 



Although their use has for the most part been limited to general construc- 

 tion, the excellent properties of the Brazilian Louros recomiended them 

 for many purposes vrhere Teak has previously been found satisfactory as well 

 as for durable construct.on, flooring, and millvTork. 



U. Goncalo Alves (A stroniu m graveolens ) . This species is a conmon tree 

 in the upland forests from "Mexico and Central /jnerica through Ecuador, 

 Colombia, Venezuela, and Brazil. Goncalo alves attains diameters of 2-3 

 feet or more and a maximum height of 120 feet. Except for narrow buttress 

 flanges extending upward from the ground for several feet, the tree com- 

 monly has a clear symmetrical bole for two-thirds of its height. 



The wood of Goncalo Alves is very heavy, averaging 63 pounds per cubic 

 foot when air dry. Strength is not high in proportion to its vreight btt 

 is nevertheless greater than that of /hite Oak particularly in compression 

 both along and across the grain. Shrinkage is appreciably less than that 

 of Oak, weathering qualities excellent, and the heartwood is highly resis- 

 tant to decay. 



The wood is used in the tropics for flooring and general construction and 

 its properties indicate suitability for durable construction. 



T- $ 



