COVE    CREEK    SULPHUR    BEDS,  UTAH.  487 
volcanic  cones,  coincide  with  it  or  lie  parallel  to  it.  The  region 
3etween  St.  George  and  Fillmore  is  known  as  a  zone  of  frequent  and 
severe  earthquakes,  several  shocks  of  sufficient  force  to  destroy  build- 
ngs  having  occurred  there  within  the  memory  of  men  still  living  in 
this  vicinity. 
SULPHUR. 
CHARACTER   OF    ORE. 
Some  of  the  sulphur  occurs  in  cylindrical  masses  or  cores  10  or  15 
?eet  in  diameter,  having  a  rude  radial  structure,  as  if  they  had  been 
formed  about  a  central  vent  that  extended  downward  into  the  beds 
yf  tuff,  but  it  occurs  mainly  as  a  dark-colored  impregnation  or 
cementing  substance  in  the  rhyolitic tuff.  In  certain  places  it  appears 
as  irregular  veins  of  nearly  pure  yellow  sulphur  ramifying  through  the 
:>eds.  These  veins,  some  of  which  are  several  inches  thick,  are  usually 
sanded  parallel  to  the  walls  and  are  evidently  filled  fissures.  The 
ulphur  is  apparently  deposited  in  some  way  from  solution,  since  in 
everal  places  acid  water,  an  analysis  of  which  is  given  below,  was 
found  issuing  from  small  fissures  partly  filled  with  yellow  sulphur. 
Here  and  there  a  small  cavity  is  lined  either  with  flowers  of  sulphur 
or  with  sulphur  crystals. 
The  ore  varies  greatly  in  richness;  at  some  places  there  is  only  a 
trace,  at  others  there  are  masses  of  practically  pure  sulphur.  Samples 
taken  at  the  extremities  of  the  workings  have  been  analyzed  by  E.  C. 
Sullivan,  of  the  United  States  Geological  Survey,  and  found  to  con- 
tain, respectively,  80  and  65  per  cent  of  sulphur.  The  first  sample  was 
taken  from  a  horizontal  sheet  8  feet  thick  and  the  second  from  a  verti- 
cal dikelike  body  4  feet  thick.  There  is  a  large  quantity  of  equally 
rich  ore  and  much  thai  is  not  so  rich.  Material  having  as  low  as  15  per 
cent  of  sulphur,  however,  is  considered  paying  ore. 
The  cost  of  production  is  doubtless  much  greater  than  it  would  be  if 
the  mining  were  done  on  a  scale  sufficiently  large  to  warrant  the  instal- 
lation of  modern  machinery.  The  stripping  to  a  depth  of  10  feet  or 
more  is  done  entirely  by  horses  and  scrapers,  much  of  the  material  hav- 
ing been  moved  several  times,  and  the  ore  is  removed  by  manual  labor, 
whereas  both  operations  might  easily  be  performed  with  steam  shovels 
at  greatly  reduced  cost. 
At  the  smelter  the  ore  is  placed  in  iron  retorts  and  the  sulphur  melted 
out  by  steam,  which  is  forced  into  it  under  a  pressure  of  about  60 
pounds,  representing  a  temperature  of  144°  C.  The  melted  sulphur 
finds  its  way  to  the  bottom  of  the  retort  and  is  drawn  off  into  iron 
receptacles,  in  which  it  cools  and  hardens  into  cakes  weighing  about 
200  pounds  each.  In  this  form  it  is  stored  until  needed,  when  it  is 
ground  into  flour  and  sacked  for  shipment.  The  rate  of  extraction  is 
slow,  but  experience  has  shown  that  an  attempt  to  hasten  it  by  raising 
