REPORT OF THE DIRECTOR I913 15 



is mounted on legs to raise the deck 2 feet 6 inches from the 

 floor level. Access is obtained by removing one of the long sides 

 by means of removable screws which work in brass sockets. In 

 practice, the interior may be furnished with block-steps or dia- 

 phragms depending on the nature of the material to be exhibited, 



Type K 



the proportions of the exhibition space yielding much latitude of 

 treatment in this respect. 



Type J. Cases of type J are also designed for the display of 

 definite specimens, that is, large minerals of a special occur- 

 rence. They are intended to be used without diaphragms or step- 



