S4« THE POPULAR SCIENCE MONTHLY 



pearls in one hundred and thirty-three days. These pearls, however, 

 are thin layers of nacre, foimed over a horny basis, which is the first 

 material to be secreted. In the natural process of continued deposi- 

 tion they increase in thickness and solidity and consequently in value. 

 One produced in a green abalone in seven months shows good form 

 and luster. My average time for drilling a hole in the abalone shell, 

 inserting the form and wiring it in place with the numbered metal tag, 

 is eight minutes. This working time might be decreased by an expert 

 laborer doing nothing else, so that the business of raising pearls would 

 be of interest and profit. Mr. C. B. Linton has succeeded in producing 

 similar culture pearls by drilling a hole through the shell center, push- 

 ing in a round ball, made from shell, and filling the outside end of the 

 hole with beeswax and cement. 



Based upon the fact that each ton of abalone shells represents a 

 certain value of manufactured jewelry and novelties, it is possible to 

 estimate the value of the abalone industry. Shells of the black abalone 

 are sorted into two classes. Each ton of those with fine, pearly centers 

 will make novelties and jewelry worth, at retail, four thousand dollars. 

 The class known as button shells, with plain mother-of-pearl surface, 

 represents a final value of one thousand dollars and the shells of the 

 green abalone, three thousand dollar?. For the fiscal year ending in 

 July, 1912, the following shipments were made from Long Beach and 

 represent the given valuations in manufactured products : thirteen tons 

 of pearl center black abalone shells, fifty-three thousand dollars; forty 

 tons of button black abalone shells, forty thousand dollars; fourteen 

 tons of dried abalone meats at two hundred dollars a ton, twenty-eight 

 hundred dollars ; a total of ninety-five thousand eight hundred dollars. 

 The shipping statistics are not complete for the other California ports, 

 but it is demonstrable that the abalone industry may be developed into 

 one of great value. 



Much has been said recently in the newspapers concerning the 

 threatened extermination of the abalone. That this is a real danger, 

 and not an idle theory, is apparent to any one familiar with the facts. 

 For instance, near Avalon, Santa Catalina Island, not more than twenty 

 years ago, the green and corrugated abalones were so thick that they 

 rested upon one another four or five deep, all over the rocks. After 

 much searching in this locality during the last year I was unable to 

 find a single specimen. The shells brought up by the divers of the 

 glass-bottomed boats, and eagerly bought by the tourists, have been 

 placed in position previously by the enterprising management. Great 

 shell heaps on San Clemente, San Nicholas and other islands prove the 

 abundance of abalones during the centuries of Indian occupation. 

 Some of the red shells found are unusually large, measuring from 

 twenty to thirty inches in circumference. Necklaces of large abalone 



