[19] FISHERIES OF THE UNITED STATES. 1019 



tories in active operation. The material used in making the glue is the 

 waste of the boneless fish factories, which, until within eight or ten 

 years, was thrown away as useless. The glue is found to be adapted 

 to many uses, and is considered preferable to cattle glue in many trades. 

 An excellent quality of guano is made from the cooked skins after the 

 glue has been extracted. From fish-oil refuse there is also made a good 

 guano. The best fish guano is made from the menhaden; several qual- 

 ities of this guano, as also the apparatus used in its manufacture, are 

 shown in the exhibit. 



