12 



tr. S. BUREAU OF FISHEEIES, 



way are grouped together in Figure 2, where F, G, H, and J rej) resent 

 all preservatives that have a heavy body, B, C, D, E, I, and L those 

 that have no heavy body, and A untreated line. 



SUMMARY OF RESULTS OF WASHINGTON EXPERIMENTS. 



1. The effects of exposure of cotton lines to outdoor weather con- 

 ditions in Washington, D. C, in winter were small; lines so exposed 

 suffered very little deterioration. 



2. All preservatives here used caused an immediate small dimi- 

 nution in tensile strength. 



3. Preservatives that have a heavy body, such as tar, by binding 

 together the fibers caused an increase in tensile strength after the 

 material became hard and dry. 



3 4 



MONTHS EXPOSED 



Fig. 2. — Tensile strength of cotton lines exposed to weather conditions at Washington, 



D. C, grouped. 



4. Tar and the petroleum product were adequate and effective pre- 

 servatives where only weather conditions were encountered. 



5. The modifications of copper oleate showed only trifling differ- 

 ences between themselves. 



SERIES EXPOSED IN SEA WATER AT KEY WEST, FLA. 

 WATER CONDITIONS AT KEY WEST. 



The sea at Key West is part of the Gulf Stream. The temperature 

 and density of the water during the period the lines were exposed 

 are shown in Table 4. The water is cnaracterized by an abundance 

 of lime. The bottom in this region is covered with a crust of lime- 

 stone, and a fine white sediment in the water deposits on the articles 

 * placed in it. It may be for this reason that the lines did not deterio- 

 rate as rapidly as was expected. There were no barnacles or other 

 marine growths on the samples returned. 



