32 



U. S. BUREAU OF FISHERIES. 

 Table 11. — Water conditions at Woods Hole, Mass. 



TESTS WITH COTTON LINES. 



MATERIALS TESTED. 



The lines tested in this series were the same as in the preceding 

 experiments, No. 24 cable-laid hard-finish cotton twine. 





I Z 3 4 



NUMBER OF MONTHS EXPOSED 



Fig. 21.— Tensile strength of cotton lines exposed in sea water at Woods Hole, Mass. 



The preservatives and preservative methods tested were the Dutch 

 method, L; copper paints Nos. 1 and 2, Q and R; petroleum product 

 No. 2, X; copper oleate followed by coal tar diluted with benzol, Y; 

 and copper oleate mixed with coal tar and the whole diluted with 

 benzol, Z; copper oleate in 15 per cent solution in gasoline, AA; and 

 the untreated line A, as control. The lines were measured and 

 weighed, as before described (p. 9), treated, and again measured 

 and weighed. The shrinkage and increase in weight will be considered 

 later. 



TENSILE STRENGTH. 



Table 12 gives the results of tensile strength measurements on the 

 unexposed and exposed cotton lines of the Woods Hole series. These 

 results are shown graphically in Figure 21 



