412 U. S. BUREAU OF FISHERIES 



Linen lines 



T Untreated— used as a control. 



NN Copper oleate — 15 per cent concentration in gasoline. This is the same 



preservative as was described under EE for cotton thread. 



00 Copper oleate — paraffin combination. This is the same preservative as 



was described under FF for cotton thread. 



PP Copper oleate — boiled linseed oil combination. This is the same pre- 

 servative as was described under GG for cotton thread. 



QQ Copper oleate — raw linseed oil combination. This is the same pre- 

 servative as was described under HH for cotton thread. 



W Quercitron and ammoniacal copper sulphate. This is the same method 



as was described under L for cotton thread. 



RR Copper sulphate. The lines were steeped in a 3 per cent aqueous solu- 

 tion of copper sulphate, removed, and dried. 



Manila hemp lines 



DD Untreated — used as a control. 



SS Copper oleate — 15 per cent solution in gasoline. This is the same pre- 

 servative as was described under EE for cotton thread. 



TT Copper oleate — paraffin combination. This is the same preservative as 



described under FF for cotton thread. 



UU Copper oleate — boiled linseed oil combination. This is the same pre- 

 servative as described under GG for cotton thread. 



VV Copper oleate- — raw linseed oil combination. This is the same pre- 

 servative as described under HH for cotton thread. 



WW Quercitron and ammoniacal copper sulphate. This is the same pre- 

 servative method as described under L for cotton thread. 



XX Coal tar. The same preservative as described under KK for cotton 



thread. 



YY Copper oleate — coal-tar combination. The same preservative as de- 

 scribed under Y for cotton thread. 



METHOD OF TAKING SAMPLES 



Irregularities in the previous year's results, which are thought to 

 have been due to variations in the samples used, made it seem desir- 

 able to standardize the samples more strictly. The method of meas- 

 uring the samples under a given pull, described in the previous report 

 on this subject, was again used. In addition to this, however, the 

 number of strands was counted in both ends of each individual 

 sample. 



It was found that many of the lines were "off-count"; that is, 

 instead of containing 24 threads, as they were supposed to, many of 

 them contained 23, 26, 27, etc. All "off-count samples were dis- 

 carded. The samples containing the proper number of threads were 

 then weighed and the average weight determined. All samples 

 weighing more than 1 gram heavier or lighter than the determined 

 average were discarded. The procedure followed gave the investiga- 

 tors a series of experimental lines all measured under a given pull, of 

 correct thread count, and not varying more than ± 1 gram in weight 

 per 75 feet of sample. After the samples had thus been carefully 

 selected they were treated with a preservative and again accurately 

 weighed and measured. 



By the above method a set of samples was obtained very much 

 more uniform than those used for previous experiments. The 

 results indicate by the smoothness of the curves that the samples were 

 more uniform. Even with this special attention to the proper 

 selection of samples there are certain irregularities in the curves 

 which can only be explained by the fact that there were differences 



