Taylor and Wells. — Preservation of Nets and Lines. 57 



note is taken of the number of oscillations the pendulum has per- 

 formed and this number is recorded as a measure of the stiffness. 

 The following table (VI) gives the number of oscillations 

 required with the different samples (Beaufort series), which 

 measures the stiffness of the lines. The more pliable the line, 

 the higher the figure. 



Table VI. — Stiffness of lines treated with the several preservatives. 

 Lines exposed to ocean water at Beaufort, N. C. 



Sym- 

 bol 



Method of treatment 



Number of oscillations 



Freshly 

 treated 



In Air 

 First month 



1 



wk 



2 



wks 



3 



wks 



In Water 

 Months 



F 

 G 

 H 



I 

 J 



L 



M 



N 



Q 

 R 

 S 

 X 



Coal tar 



Pine tar 



Pine tar and coal tar 

 mixed 



Bull's method 



Petrolexmi Product, 

 No. 1 



Dutch method 



Copper oleate, 8 mg. 

 copper per yard 

 length 



Copper oleate, 12 mg. 

 copper per yard 

 length, 5% oil 1- 

 1,000 cresol 



Copper oleate, 18 mg. 

 copper per yard 

 length 



Copper oleate, 18 mg. 

 copper per yard 

 length, 2% oil 



Copper paint, No. 1 . . 



Copper paint, No. 2 . . 



Gilsonite 



Petroleum Product, 

 No. 2 



25.0 

 29.9 



24.2 

 45.1 



29.0 

 44.9 



60.5 



19.7 

 19.9 



18.0 

 40.7 



20.3 

 39.9 



17.2 

 17.6 



18.4 

 38.3 



15.9 

 17.5 



16.3 

 43.7 



17.9 

 40.1 



19.3 

 15.0 



18.9 

 14.8 



18.014.8 

 44.835.9 



52.3 45.5:44.1 



59.1 51.341.036.9 



50.2 



49.6 



18.2 

 44.3 



74.3 



61.4 



18.1 

 45.5 



16.6 

 18.1 



16.6 



37.0 



18.2 

 33.8 



16.1 



27.4 



16.5 



X 

 X 



33.6 



71.856.646.4 



63.968.4 



43. 437. 9i38. 560. 956. 853.0 



70.1 



45.9 



43. 3!38. 4135. 864. 357. 5:55. 5 



31.1 32.7 



29.4 !31.3 



36.5 i25.5 



34.3 



64.7 



30. 4129. 139. 329. 3:31. 039. 6 

 28.7i26.1 14.626.4'33.923.6 

 22.0:17.321.1117.2 18.021.3 



29.227.0122.318.723.5 



18.0 

 34.2 



19.2 



X 



X 



41.7 



46.7 



62.8 



58.4 



35.3 

 28.2 

 23.3 



X 



X Indicates that line was disintegrated. 



Figure 10 shows the result graphically for the individual 

 lines. It will be noticed that, although each line shows fluctua- 

 tions from month to month that may not have significance for 

 our purpose, the lines naturally divide themselves into groups of 



