280 PROCEEDINGS OF THE 



charges might be taken for various kinds of untreated 

 and treated timbers. 



TABLE SHOWING ANNUAL CHARGES. 



Timber and Length of Original Cost of Annual 



Treatment. Service. Cost. Treatm't. Charge. 



White oak, untreated loyrs. $0.85 $0.121 



Red oak or loblolly pine, 

 untreated Syrs. .40 .124 



Red oak or loblolly pine, 

 with zinc chloride treat- 

 ment loyrs. .40 $0.16 .085 



Red oak or loblolly pine, 

 with zinc creosote treat- 

 ment l6yrs. .40 .25 .065 



Red oak or loblolly pine, 

 with creosote treatment.. 2Oyrs. .40 .45 .069 



The conclusion to be drawn from such a table is that 

 the treated timber in every case is cheaper in the long 

 run than the untreated timber; furthermore, that the 

 better treatments, although more expensive at first, are 

 very much cheaper in the long run. One ought to add 

 that the treatments given above were selected from a 

 long list, as representing extremes and averages of 

 cost. 



Having reached the conclusion that timber preser- 

 vation is worth considering; in other words, that it 

 makes possible the utilization of timbers not generally 

 used, and that it pays, one may consider somewhat 

 more in detail some of the problems connected with 

 preservation. One cannot dwell too frequently upon 

 the sentence that timber preservation is not merely an 

 injection of salts or chemicals into wood. I have stated 

 elsewhere that it involves not only the successful injec- 

 tion of chemicals, with all that that implies, but also 



