92 



those on the San Francisco side, while Lininoria is much less unfavorably affected on 

 the Oakland side, would seem to indicate from the above records that blue gum Euca- 

 lyptus resists the attack of Limnoriu better than does Douglas fir, but that of Teredo 

 and Bankia little if any better. 



The cjuantity in which blue gum Eucalyptus is available in piling size and form is 

 too restricted and uncertain to make it a large factor in that situation, even if more 

 highly suitable than it is. For wearing blocks, or stub piles, usually extending down 

 to about low water only, and bolted between the standing piles of the spring line to 

 take boat friction and other wear, mechanical life is short in any case. The great 

 hardness and toughness of the ecualyptus gives it excellent serviceability for this use, 

 which is now expanding. For this purpose the supply is probably adequate. 



Foreign Woods 



As has already been stated, the foreign woods, of which there are a considerable 

 number which appear to have specific resistance to marine wood borers, are none of 

 them at the present time able to meet on a competitive basis the cost of the creosote 

 treated Douglas fir pile. Marvellous tales are current respecting the life of some of 

 these foreign woods in borer infested waters, and in some cases appear to be supported 

 by credible evidence, e. g., 75-year life of turpentine wood in the Philippine region, 

 and of manbarklak in piers at Maracaibo, Dutch Guiana. The test made of some such 

 woods by the Committee was, of course, much too short to disclose anything sig- 

 nificant. In the following partial list, the woods thus tested by the Committee are 

 starred. Test result comments following these species, referring to the Committee 

 exposure tests, can be followed in detail by reference to the tabulations in Chapter XI. 



FOREIGN WOODS CL.^LMED TO BE 

 RESISTANT TO M.ARINE BORERS 



From African Kamcrun : 



*Azobe (Laphira procera). Unattacked in Committee test. 

 Australian or New Zealand woods : 

 Totara (Podocarpits totara) 



Matai (Podocarpus spicata). Podocarpiis elala also said to be resistant. 

 *Turpentine wood (Syncarpia laiirifolia). No attack. 

 Grey bo.x (Eucalyptus hcuiiphloia) 

 Ironbark (Eucalyptus sideroxylon and E. pauiculata) 

 Jarrah (Eucalyptus maraiuata) 

 Red gum (Eucalyptus rostrata) 



*Tallow wood (Eucalyptus macrocorys). Showed slight attack in two years. 

 Philippine woods (in order of resistance): 



Liusin or Cretalingan (Parinarium corymbosum) 

 Aranga (Ilomalium luzoniense) 

 Betis (Bassia bet is) 

 Dungon (Tarrietia sylvatica) 

 Dungon late (Ileritiera Uttoralis) 

 Molave (Vitex parviflora) 

 South American woods: 



*Greenheart (Nectandra rodioei) 



Slightly attacked in three years in Committee tests. Attack moderately 

 heavy in nine years in Forest Service tests at San Diego. Said to have 

 failed seriously in Panama Canal work. 

 *Manbarklak (Eschwellera corrugata) 



