Oct.  1897. 
Annual  Report  of  the  Director. 
expended  has  been  marked,  and  with  the  possible  exception  of  two 
halls,  the  system  of  installation  now  exhibited  through  the  depart- 
ment may  be  considered  permanent.  To  the  cases  in  the  Paleonto- 
logical  halls,  which  contain  the  fossils  of  the  geological  period,  large 
framed  maps  showing  the  distribution'of  these  rocks  in  the  United 
States  have  been  added,  thus  giving  opportunity  for  locating  the 
forms  of  the  period.  The  educational  value  of  the  systematic  mineral 
collection  has  been  increased  by  neat  case  labels  which  give  the 
composition  and  system  of  crystallization  of  each  species.  The  col- 
lection illustrating  structural  geology,  has  been  so  largely  increased 
that  an  entire  re-arrangement  has  been  necessitated  and  part  of  the 
specimens  have  been  transferred  to  Hall  66.  A  collection  illustrat- 
ing the  rocks  of  the  Saarbrucken  coal  fields  has  been  brought  from 
storage  and  also  placed  in  this  hall,  together  Avith  a  series  of  rocks  of 
Popocatepetl  and  Ixtaccihuatl  collected  by  the  Curator  in  Mexico. 
From  the  large  marble  structure  formerly  shown  in  Hall  67,  slabs  of 
uniform  size  have  been  cut,  so  as  to  illustrate  the  different  varieties 
of  marble  which  they  represent.  These,  together  with  specimens 
obtained  from  other  sources,  have  been  installed  in  large,  upright  and 
well  lighted  cases  in  the  hall  and  given  a  geographical  arrangement. 
Thus  an  extensive  collection  consisting  of  about  350  specimens  has 
been  obtained,  which  represents  the  principal  varieties  of  marbles 
from  France,  England,  Italy  and  the  United  States,  as  well  as  many 
varieties  of  serpentine  and  onyx.  In  this  form  the  collection  proves 
to  be  far  more  instructive  and  attractive  than  before.  In  Hall  68 
the  pyramids  made  up  of  building  stones  of  irregular  sizes  have  been 
removed  and  the  specimens  which  they  contained  have  been  cut 
to  cubes  of  uniform  size.  These  are  now  installed  in  systematic 
order  in  cases.  With  these  and  other  additions,  the  building- 
stone  collection  now  includes:  granite  from  sixty-seven,  sandstone 
from  ninety,  and  marble  from  eighty-eight  localities,  with  about 
sixty  miscellaneous  specimens.  In  Hall  69  the  cases  have  been 
repainted,  —  printed  labels  giving  complete  information  regarding 
each  specimen,  including  its  analysis,  have  been  put  in  place, 
and  thorough  treatment  has  been  given  to  each  specimen  when 
necessary  to  prevent  its  decay.  The  oils  in  Hall  71,  which  had 
become  discolored  through  decomposition  have,  through  the  gener- 
osity of  the  Standard  Oil  Co.,  been  replaced  by  fresh  specimens, 
and  some  improvements  in  installment  have  been  made.  By  careful 
selection  and  arrangement  of  material  already  on  hand,  a  series  of 
collections  illustrating  several  different  ]  processes  of  extraction  of 
lead  and  silver  have  been  put  in  place  in  Hall  72  and  given  a  graphic 
