THE FOREST PRODUCTS LABORATORY 

 Wood preservation. Open tank treatment on the Ml; commercial trca:ing pljnl in the centre 



wood most effectively with the pn>erv- 

 atives. 



To study the first class of these prob- 

 lems, the laboratory is provided with a 

 fungus pit, which contains chambers in 

 which the wood can be thoroughly in- 

 oculated with various destructive fungi. 

 The humidity and temperature of tlu 

 pit can be regulated to produce condi- 

 tions most favorable to fungus growth. 

 Woods treated with different preserva- 

 tives are placed in this pit, where they 

 can be isolated in chambers. The ef- 

 ficiency of the preservative is iivlic. 

 by the ability of the wood treated with 

 it to ward off the attacks of fungi un- 

 der these conditions. 



The second class of problems involv- 

 ing the impregnation of wood an- 

 chiefly those of mechanical engineering 

 and the plant of the laboratory is mo<-t 

 complete in this respect. It is, in fact, 

 a reproduction of a fully developed 

 commercial plant. The machim-rv 

 provided for forcing any required 

 amount of preservative into the species 



and form- <>f wood which ma\ 

 tested. This i- d'mr under high pre 

 i;rc. and the treated cylinders are tesl 

 for great resistance. The outfit 



eludes one treating cylinder thp 

 nc-half feet in diameter and twe 



i in length, which will wiih'-'am 

 working pre-nre of 300 pound- to 

 square inch. There i- al >0 a -mall i 

 perinicntal cylinder one and one li 

 feet in diameter and three fei-t loi 

 de-igned to withstand a working pre 

 nre of 600 pound-, to the quatt in 

 This apparatus i < onn< < ted with a - 

 tern of tanks, force, air, and va< 11 

 pump- for handling the < j,i - ei V&i i 

 and forcing them into the wood. I li 



il-o an open lank outfit loi ih- i 

 pier treatment <,f butt .,f j,,, t , 

 pole-, -IK h pi a' tji able foi t'ai in 



and other- n-,ing nin< h of (hi mat' i 



bui. not enough t't j M ni having 



COUrse to a < omnier' ial plant In I 

 < onne< tion it may b ( '"'" I'd I 

 time only ' an t II what and h 

 much \\\><-\\<>r vain- th-- clo ' d I: 



