THE HAWK'S-BJLL TURTLE. 181 



The total value of our imports in one year is 

 estimated at about twenty-five thousand pounds. 

 The greater proportion of this is derived from 

 the British East Indies, and the residue from 

 Central and South America, Australia, Egypt, the 

 West India and Philippine Islands. 



The mode of working this substance is de- 

 scribed at some length by MM. Dumeril and 

 Bibron, in their large work on " Reptiles." In 

 order to straighten the plates, which, when de- 

 tached, are bent in various ways, it is sufficient 

 to steep them in boiling water for a few minutes, 

 and then take them out and place them between 

 plates of metal or smooth blocks of hard wood, 

 leaving them to cool, great pressure being em- 

 ployed at the same time. They then retain the 

 flatness desired. They are next scraped and 

 filed, a smooth surface being obtained with as 

 little loss as possible. When these shells or 

 scales are brought to a proper thickness and 

 size, they may be then used separately ; but they 

 are generally submitted to a still further pre- 

 paration. When, for instance, they are too thin, 

 or when they are not sufficiently long or broad, 

 the following processes are employed : In order 

 to obtain single plates of great size, two are 

 soldered together, the thin part of one being 

 laid upon the thin part of the other; or, as is 

 .^sometimes done, the edges of each plate are 



