XXIV REPORT OF THE COMMISSIONER OF FISHERIES 



iiing- as sardines. Fundamental knowledg-e of this procedure was 

 needed to make possible further etfective work upon the develop- 

 ment of a new method. This information was therefore obtained. 

 Now for the first time data are at hand which will enable drying 

 equipment used in the sardine-canning industry to be designed upon 

 a scientific basis. Advantage has already been taken of this fact 

 within the industr}-, with very good results, in the building of new 

 equipment and the improvement of old. It has been shown that 

 fish may be dried for frying in from one-third to one-fifth the 

 time formerly required. The size of the efjuipment ma}' also be 

 decreased correspondingly. 



The real outcome of the drying research and the studies which 

 preceded it has been the development of a new process of preparing 

 fish for canning. This process depends upon rapidly moving hot air 

 to cook and dry the fish simultaneously, followed by cooling in a 

 blast of cold air so that they may be packed immediately. The time 

 required for carrying out this j^rocess has been reduced to about 

 40 minutes for the largest California pilchards, and operation can be 

 continuous. In the fr^^ing-in-oil method now in use the fish are dried 

 at least 30 minutes, fried 7 to 10 minutes, and allowed to drain and 

 cool overnight before being packed. Fish prepared in the new man- 

 ner are not open to the objections raised against fried fish. 



Experiments with the process have successfully passed through 

 small and semilarge scale operation, and plans are now being made 

 by the industry in California for the first large-size installations. 

 It is believed, and this view is generally shared by the packers, that 

 in time this process, or some modification thereof, will be the one 

 in common use. 



PRESERVATION OF NETS 



With the publication, during the last fiscal year, of the results 

 obtained in the bureau's experiments with copper oleate as a net pre- 

 servative, the point Avas reached where commercial fishermen could 

 take advantage of this information. The manufacturers promptly 

 took up its manufacture and were able to meet the large demand 

 created by the adoption of copper oleate as a net preservative by com- 

 mercial fishermen. Its use has already passed beyond our own 

 borders into other countries. 



A recent survey of the New England and Middle Atlantic States 

 showed that copper oleate is being used on a commercial scale with 

 very satisfactory residts on the whole. There still remains some 

 difficulty in certain localities in satisfactorily checking the deteriora- 

 tion of nets. Experiments to obviate these difficulties have been 

 continued. It has been found that the excessive solubility of cop])er 

 oleate in the water is effectively prevented by a combination with 

 tar, and Avhere a stiffness in the net is not objectionable, this ]ire- 

 servative is highly satisfactory. Experiments showed further that 

 re-treating lines in fresh water at 80-day intervals more than doubled 

 their life. Most users of copper oleate found that in applying copper 

 oleate better results were obtained when the net Avas soaked in a 

 solution for several hours instead of dipping it in the solution for 

 a shorter interval. 



