Taylor and Wells. — Preservation of Nets and Lines. 



59 



or else cause shrinkage ; none have been encountered which cause 

 increase of length. The changes in length have been ascertained 

 for all preservatives studied by measuring the line before treat- 

 ment under a constant pull of 2 kilograms, and after treatment, 

 under the same conditions. Duplicate measurements are re- 

 peated to an accuracy of about 4 inches in 100 feet, that is, within 

 .33 per cent. It was impracticable to make these measurements 

 under constant temperature and humidity conditions, because of 

 the large space required to stretch and measure the samples, 

 and no room equipped for constant atmospheric conditions and 

 of sufficient size was available. The following table VII, and 

 Fig. 12, show, however, that the change is small, at greatest, so 

 that errors caused by changing temperature and humidity would 

 be negligible. 



Table VII. — Shrinkage of No. 24 cotton lines caused by the application 



OF various preservatives. 



Symbol 



Method of treatment 



Per cent shrinkage 



B 

 C 

 D 

 E 

 F 

 G 

 H 

 I 



J 



K 



L 



M 

 N 

 O 

 P 



Q 



R 

 S 

 X 



Copper oleate, 7% 



Copper oleate, 7%; 5% oil; 1-1,000 cresol. . 



Copper oleate, 11% 



Copper oleate, 11%; 2% oil 



Coal tar 



Pine tar 



Coal and pine tar, 50% each 



Bull's method 



Petroleum Product, No. 1 



Waterproofing material 



Dutch method 



Copper oleate 7 J^% 



Copper oleate 7^%; 5% oil; 1-1,000 cresol. 



Copper oleate, 12 H% strength 



Copper oleate, U}4%; 2% oil 



Copper paint I 



Copper paint II 



Gilsonite 



Petroleum Product, No. 2 



.91 

 .98 

 1.67 

 1.14 

 2.48 

 2.51 



.41 



1.07 



.99 



.85 



.65 



2.87 



1.22 



Noticeable shrinkage occurs only in the case of lines treated 

 by hot aqueous bark extracts, Bull's method, and the Dutch 

 method. But none of the methods causes enough shrinkage to 

 make this an item of any practical importance. This factor 

 should be considered, however, in connection with aqueous 

 preservatives, especially those applied hot or repeatedly. 



CHANGES IN WEIGHT CAUSED BY THE APPLICATION OE PRESERVATIVES. 



All the preservatives studied increased the weight of the 



