FISH-NET PRESERVATIVES. 



15 



and thus increased the tensile strength, while the copper oleate did 

 not stick the fibers, but by its preservative action prevented decay 

 and held the lines throughout the test up to their original strength. 

 The lines preserved with copper oleate did not show great differences 

 between themselves, nor do the different kinds of tar show important 

 differences. 



42 



40 



36 



z 



2 ^ 



I- 



S 30 



I- 



«o 

 ui 28 



-J 



£ 26 



d IZ 



WEEKS EXPOSED 



Id 



Fig. 4.— Tensile strength of cotton lines exposed in sea water at Key West, Fla. 

 grouped. 



SDMMAKY OF RESULTS OF KEY WEST EXPERIMENTS. 



1. Exposure to sea water at Key West had a severer action on 

 cotton lines than the weather at Washington, D. C. 



2. Quercitron and potassium bichromate, petroleum product, and 

 the proprietary waterproofing material showed no noteworthy pre- 

 serving effect. 



3. The Dutch method was somewhat better, though the lines 

 treated by it showed marked deterioration in four and one-half 

 months. 



4. The lines preserved with copper oleate showed no substantial 

 deterioration in six months' exposure at Key West; an immediate 



36199°— 23 2 



