244 MARINE PRODUCTS OF COMMERCE 



of yards of linen in a given pound of thread, multiply the lea by 300 and divide 

 by the number of cords. For example, one pound of ^%-linen thread would be 

 1,500 yards long. 



Synthetic Fibers. As far as is known the first synthetic, or man-made, fiber to be 

 successfully developed was called "artificial silk" and was shown at the Paris 

 Exhibition in 1889. Though a poor example, it was nevertheless the beginning of 

 the modem synthetic fiber industry. 



Nylon, first called "Fiber 66," made its appearance in 1938. An American in- 

 vention, it has no counterpart in any other product in the world. This fiber can be 

 best characterized by its extreme toughness, strength, and light weight. Since 

 World War II started at about the time that nylon was introduced into the fishing 

 industry, it was restricted for use by the armed services. In 1946 these restric- 

 tions were lifted, making it available for the second time. 



Nylon appears to possess the best characteristics for displacing natural fibers 

 in marine fisheries' applications. Because at the time of this writing only a small 

 quantity has actually found its way into the fishing industry, it is difficult to pre- 

 dict its future. 



Another synthetic fiber, known as "Orion," was announced late in 1948. Since 

 it has been reported to have been developed for marine uses, it may compete with 

 nylon in this field. 



Although nylon fibers are processed into twine, rope, etc., in much the same 

 manner as the natural fibers, they are classified into various sizes by the term 

 "denier." The size, therefore, is the weight of a 450-meter (1,500 feet) skein of 

 fiber in deniers, 1 denier equalHng 5 eg, 20 deniers equalling 1 g (i/454 pound). 

 They can be sized by weight because the diameter of nylon fibers is so uniform. 



Netting Terminology. Fishermen generally call fish netting "webbing" or "twine" 

 to distinguish it from a rigged net. Rigged nets are "hung" nets and include not 

 only the webbing but all necessary attachments, such as floats, sinkers or leads, and 

 the cordage to which they are all secured. The term "gear" is used when re- 

 ferring to a complete net. 



Netting manufacturers produce the webbing in long continuous sheets, as in 

 other types of textile manufacture. Instead of rolling it on spools as it comes off 

 the loom, it is laid in folds. Because of its bulk the netting is pressed into bales 

 before shipping. It is sold by the pound. 



When finished nets are ordered, the manufacturer requires from the customer 

 a pattern containing all the specifications from which the net is tailored. Stand- 

 ardization of fish nets is practically nonexistent, with the exception of such gear 

 as otter trawls, fyke nets, etc. For this reason the majority of netting is sold as 

 straight webbing, conforming to the mesh and twine sizes specified. The depth 

 of a net is actually the width of the webbing as it comes oflr the loom. The pur- 

 chase of netting is, for the reasons shown here, a matter of importance not only 

 to the fishermen, but to the manufacturer as well. 



The size of a mesh is always given as the stretched measure (i.e., a mesh 

 measuring 1 inch on each of the four bars, or legs, would be termed a 2-inch 

 mesh). Measurements are taken from the center of the upper knot to the center 

 of the lower knot by inserting a thin ruler inside the upper knot, drawing the legs 

 of the mesh together until they are taut, and recording the length to the outside 

 edge of the lower knot. In other words the mesh size includes only one full knot. 



