124 TIMBER 



or is more pleasant to use than greenheart, but it has 

 one disadvantage, that of being more brittle than split 

 cane." 



The greenheart which comes from British Guiana is 

 more appreciated than that which grows in Dutch Guiana, 

 even on the Continent, where a large quantity of the latter 

 is imported. 



The weight is generally given as from 60 to 70 Ibs. per 

 cubic foot. Two good samples, the cross sections of large 

 logs, weighed by the author, gave about 71 Ibs. 



Greenheart withstands the attack of the teredo better 

 than most wood ; many engineers consider that it is only 

 the sapwood which is attacked and that the worm only 

 goes a couple of inches into the log. Even in Bombay 

 waters, where the teredo is particularly voracious, green- 

 heart dock gates stood without serious damage for nearly 

 ten years and then only required slight repair ; pine 

 timber would be destroyed there in a few months, and 

 teak in a few years. The attack of the sea worm on green- 

 heart, that of the limnoria especially, is very slow in 

 Great Britain ; unprotected greenheart piles stand per- 

 fectly sound after being in a situation for over twenty 

 years, where unprotected pine timber would have been 

 destroyed in half the time. The most decisive evidence 

 that greenheart piles are not proof against the teredo has 

 come to the writer's notice lately. A large pier in the 

 Mediterranean, with the construction of which he was 

 associated, was built of this timber twenty years ago, and 

 is now so seriously damaged by the worm that it is being 

 replaced with ferro-concrete. This is in a locality where 

 the teredo is particularly destructive. The greenheart 

 decking which was on this pier is in such good condition 

 after twenty years' exposure that it is intended to replace it 

 on top of the new concrete piles. Greenheart is a timber 



