FISH-NET PRESERVATIVES. 3 



but no less obvious is its importance when considered as a part of 

 our national economy. 



Table 1. — Number and value of fishing nets in the United States. 



Seines 



Gill nets 



Trammel nets 



Poimd nets, trap nets, and 



weirs 



Fyke nets 



Stop nets 



Hoop nets, pots, and traps. . . 

 Beam trawls 



Number. 



5,440 



223,890 



3,312 



17,968 



62, o70 



207 



23,017 



37 



Value. I 



$1,877,278 



4, 1%, 592 



116,611 



6,355,281 



449, 247 



13,367 



44,819 



4.835 



otter trawls 



Paranzella nets 



Lampara nets 



Lines 



Eel pots and traps. 

 Lobster pots 



Total. 



Number. 



1,287 

 44 

 65 



23,792 

 247,324 



Value. I 



$74,017 

 9,000 



29,500 

 514,913 



28,695 

 623, 475 



14,337,630 



1 These figures, obtained in the regular canvasses of the fisheries, represent not new value but values of 

 the gear owned by the fishermen at the time of the canvass. 



One would think, in view of these facts, that the art oi preserving 

 nets effectively would already have reached a high degree of perfec- 

 tion, but it has not done so. The literature of the subject is very 

 small; the number of scientific papers reporting serious research into 

 the subject can almost be counted on one's fingers. The conclu- 

 sions found in the few papers reviewed are mostly inadequate, dealing 

 as they do mainly with the factor of tensile strength and being based 

 on too short periods of exposure. Furthermore, the principal mate- 

 rials used for net preservatives seem to have come into use for insuf- 

 ficient reasons. Tar, the commonest material, appears to be used 

 principally because it is available, cheap, and does some good, though 

 never developed especially to meet any particular requirement, and 

 indeed answering rather poorly most of the requirements of a good 

 all-round preservative. Tanning extracts seem to have come into 

 use through reasoning by a false analogy that if tanning preserves 

 skins it will preserve cotton and linen lines also. As a matter of 

 fact, there is no chemical similarity between cotton or linen and 

 animal skins, and, as will be seen later, very little good results from 

 the use of tanning materials alone on cotton or linen. 



The plain need is therefore obvious. The various preservatives 

 now available should be subjected to thoroughgoing scientific investi- 

 gation to determine their suitability and effectiveness in every way 

 as general or special preservatives, and a serious effort should be 

 made to produce a material that really meets the many requirements 

 of a suitable, efficacious, and all-round preservative of fish nets. 

 The present paper will report results of experiments and tests made 

 during the past two years with these objects in view. 



GENERAL SUMMARY. 



The principal results and conclusions arrived at and reported in 

 detail in the main part of this paper following are here summarized. 



1. The following preservatives and preservative methods were 

 tested: Coal tar, pine tar, coal and pine tar mixed, two proprietary- 

 petroleum products, quercitron and potassium bichromate, the Dutch 

 tanning method, copper oleate in nine variations, two proprietary 

 copper paints, a proprietary waterproofing compound, gilsonite (sold 



