Pl.  XII.    Details  of  Adjustable  Shelves  on  Fixed  Uprights. 
Supports  and  cross  bars  are  of  the  same  size.  Castings  and  bars  are  oxidized. 
Glass  shelves  ;  ebony  case. 
Details  of  Adjustable  Swinging  Shelf. 
The  supports  are  y%  inch  and  cross  bars  %  inch  gas  pipe,  finished  as  desired. 
Castings  all  in  brass.  Interference  of  thin  piece  of  linoleum  at  center  brings 
greatest  weight  on  heaviest  roof  cross  bar.  Shelves  may  be  of  different  widths, 
lengths  and  elevations. 
Detail  of  Koor  Cases  Used  for  Exhibiting  Marbles  and  Ornamental  Stones, 
These  cases  have  been  designed  with  the  view  of  obtaining  the  maximum 
amount  of  light  from  overhead  lighting,  with  a,  minimum  amount  of  frame-work. 
They  also  provide  adjustable  shelving.  They  are  3  feet  7  inches  wide,  9  feet  9 
inches  long  and  8  feet  7  inches  high,  with  base  2  feet  2  inches  high.  Four  braced 
uprights  in  the  center  of  the  case  furnish  support  for  the  shelves.  These  are 
provided  with  Jencks'  adjustable  brackets.  The  brackets  are  of  such  length  as 
to  allow  each  shelf  to  project  two  inches  beyond  the  one  above  it.  The  speci- 
mens rest  at  the  bottom  in  a  groove  in  the  shelf  and  at  the  top  against  a  flange 
dropped  from  the  shelf  above.  When  the  case  is  filled  the  specimens  form  a 
four-sided  pyramid,  all  parts  of  which  are  equally  lighted.  The  inclination  of 
the  slabs  also  favors  reflection  of  the  light  from  their  surfaces  rather  than  from 
the  glass,  and  serves  to  light  the  interior  of  the  case. 
