ECONOMIC USES OF NON-EDIBLE FISH. 



67 



the drying field comprises nearly twenty acres. From first to 

 last the greatest care is taken that no foreign substance shall be- 

 come mixed with it. When it is sufficiently dry it is bagged for 

 transportation, either to the manufacturer of artificial fertilizers 

 or direct to the farmer. The total quantity of menhaden " scrap " 

 manufactured during the nineteen years from 1874 to 1892 inclu- 

 sive was 912,467 tons (dry and acid), and the amount made from 

 other non-edible fishes and waste fish in the United States is esti- 



FIG. 4. INTERIOR OF CURB KOOM IN FACTORY, SHOWING THE IRON CYLINDERS IN WHICH 



THE SCRAP is PRESSED. 



mated at 150,000 tons. By analysis, the average percentage of 

 nitrogen was found to be eight per cent in the dry scrap and six 

 per cent in the acid, while the acid guano contained four per cent 

 of phosphoric acid, and the dry seven per cent. This gives us a 

 total plant food (nitrogen and phosphoric acid) of 135,000 tons, or 

 about $31,000,000 worth at the present rate fixed by the New Eng- 

 land experiment stations. 



The average price at which this fish guano was sold was fifteen 

 dollars per ton for the acid scrap and twenty-five dollars for the 

 dry. The guano from the Peruvian deposits which has been im- 

 ported into this country during the past thirty years contained 

 from four to eight per cent of nitrogen, with about an equal per- 

 centage of phosphoric acid, and millions of dollars have been paid 

 for it at the rate of from forty-five dollars to eighty dollars per 

 ton. Why such a great disproportion exists in the prices seems 



