Potash from California Sea Kelp 



Subterranean reapers harvest the product 



The harvester 

 waiting for the 

 tide to come in 

 before it con- 

 tinues its un- 

 dersea kelp-cut- 

 ting operations 



THE potash 

 problem has 

 been successfully 

 solved. Our supply of 

 raw material for its manu- 

 facture costs little and is practically inex- 

 haustible. Near San Diego, California, un- 

 dersea reapers are harvesting kelp, from 

 which potash equal to about three times our 

 annual importation from Germany previous 

 to the war, is made by one concern; a 

 second plant of about equal capacity has 

 been established in the same vicinity, and a 

 smaller plant installed by the Government 

 is in operation. Just now, the manufacture 

 of munitions requires all that can be pro- 

 duced, but we can obtain all that is re- 

 quired for ourselves and our allies. 



The reaper cuts the weed four feet below 

 the water surface when empty and six 

 feet when loaded, the depth having been 



made a Government regulation for conserv- 

 ing the supply. Each of the three boats 

 in the Hercules fleet takes about five hun- 

 dred tons every working day, which means 

 practically every day in California. The 

 cut kelp is carried aboard the harvester 

 on a continuous belt elevator to a mill, 

 where it is crushed. The resultant sticky, 

 gelatinous mass, deposited in the storage 

 hopper, contains about eighty per cent 

 water. This is pumped through a six-inch 

 pipe. As soon as a capacity load is ready 

 it is transferred by pumps to barges and 

 thence into digestive tanks on the wharf, 

 each of 50,000 gallons capacity. Subsequent 

 processes deal with evaporation. 



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