FURTHER EXPERIMENTS ON THE PRESERVATION OF 



FISH NETS ' 



By Harden F. Taylor, formerly chief technologist, and Arthur W. Wells, 

 assistant technologist, U. S. Bureau of Fisheries 



CONTENTS 



Page 



Introduction 409 



Conclusions 410 



Experimental exposure and testing of lines 411 



Notation of samples 411 



Method of taking samples 412 



Series exposed in sea water at Beaufort, N. C 413 



Series exposed in sea water at Boothbay Harbor, Me 414 



Series exposed in sea water at Astoria, Oreg 417 



Series exposed in fresh w^ater at Put in Bay, Ohio 420 



Series exposed in fresh water at Charlevoix, Mich 423 



Series exposed in fresh water at Fairport, Iowa 425 



Series exposed in fresh water of the Potomac River at Washington, 



D. C 432 



Increase in weight caused by application of preservatives 434 



Shrinkage caused by application of preservatives 434 



Effect of exposure to sunlight 435 



Results of practical application of copper oleate by fishermen 436 



Bibliography 437 



INTRODUCTION 



In a previous paper,' published in 1923, results were reported of a 

 series of tests made on cotton and linen thread with the view of 

 determining what preservatives were most effective. Copper oleate, 

 a substance the use of which for purposes of net preservation was 

 first proposed and tried by the writers, was given particular con- 

 sideration. Data of much value were obtained from this series, but 

 there still remained many phases of the work upon which more com- 

 plete information was desired. Therefore, a second series of tests 

 was prepared, much larger than that already reported and including, 

 in addition to cotton and linen thread, a number of samples of 

 manila hemp. The results of these experiments, together with 

 information obtained from actual trials by fishermen of some of the 

 preservatives, are reported in this paper. 



The preservatives and preservative methods tested included copper 

 oleate alone and in comoination, tar, tanbark, and numerous pro- 

 prietary substances used as preservatives. The tests were made in 

 salt water at two places in the Atlantic Ocean, one place in the 

 Pacific Ocean, and in fresh water at four places. 



1 Appendix VIII to the Report of the U. S. Commissioner of Fisheries for 1925. B. F. Doc. 998. Tech- 

 nological contribution No. 23. 



2 Properties and Values of Certain Fish-net Preservatives. Appendix I, Report of the U. S. Commis- 

 sioner of Fisheries for 1923, 69 pp., 35 figs. B. F. Doc. 947, 1923. 



Note. — The Bureau of Standards, Department of Commerce, through its division of textiles, cooperated 

 freely with the Bureau of Fisheries in furnishing apparatus and facilities in a room of constant temperature 

 and humidity for making the measurements of tensile strength. 



409 



