THE most notable progress yet recorded in the chemical 

 treatment of timber to prevent decay was made in 

 1913, according to a report recently issued by the 

 American Wood Preservers' Association in co-operation with 

 the forest service of the department of agriculture. 



The report states that 93 wood-preserving plants in 1913 

 consumed over 108 million gallons of creosote oil, 26 million 

 pounds of dry zinc chloride, and nearly 4 million gallons of 

 other liquid preservatives. With these the plants treated over 

 153 million cubic feet of timber, or about 23 per cent more 

 than in 1912. The output from additional plants unrecorded 



.would increase the totals given. 

 Impregnation of wood with oils and chemicals to increase 

 its resistance to decay and insect attack, the report goes on 

 to say, is an industry which has become important in the 

 United States only in recent years. In Great Britain and 

 most of the European countries practically every wooden 

 cross-tie and telephone or telegraph pole receives preserva- 

 tive treatment. In the United States less than 30 per cent 

 of the 135 million cross-ties annually consumed are treated, 

 and the proper treatment of an annual consumption of 4 

 million poles may be said to have scarcely commenced. 



Real progress in the United States dates from 1832, when 

 the Kyanizing process, using bichlorides of mercury, was 

 developed. In 1837 two other processes were introduced, the 

 Burnett process using zinc chloride, and the Bethel process 

 using coal tar creosote. These last processes are very largely 

 in use today. 



The idea of timber preservation at first made very slow 

 growth in this country, on account of the large supply of 

 cheap and durable timbers and the general disregard shown 

 toward economy in the use of natural resources. In 1885 

 there were only three pressure plants in the United States; 

 and in 1895 only 15. Since then, however, the industry has 

 grown rapidly; in 1913 there were 117 plants. 



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