342  CONTRIBUTIONS    TO    ECONOMIC    GEOLOGY;  1906,  PART    I. 
Elk  city.  :\\  miles  south  of;  bed  at  top  of  rise  imder  Lighl  cover. 
Piney,  2\  miles  southwesl  of,  and  Zion  churches,  I  mile  northeast  of;  a  few  frag- 
ments. 
Piney,  2\  miles  southeast  of,  on  road  leading  to  Five  Points  schoolhouse. 
Sligo,  2\  miles  northeast  of  and  just  southwest  of  schoolhouse;  clay  apparently  of 
excellenl  quality. 
Reidsburg,  I  mile  north  of,  on  road  to  Clarion. 
Clarion-Williamsburg,  road  between;  clay  shows  at  several  places,. at  some  in  con- 
siderable thickness,  bu1  of  inferior  quality. 
Mechanicsville,  II  miles  aorthwesl  of,  on  road  to  Clarion;  2  feel  exposed. 
Mechanicsville,  one-half  mile  easl  oj',  south  of  crossroads;  inferior  quality,  black  and 
knotty. 
Mechanicsville,  l  mile  easl  of,  on  road  to  Waterson  station;  3  feet  exposed. 
Mechanicsville,  I  mile  easl  of,  on  north  and  south  road  at  top  of  hill;  bed  under 
lighl  cover. 
Clarion-Strattonville,  road  between;  several  exposures. 
Strattonville,  I  \  miles  south  of,  and  Rehoabeth  church,  one-quarter  mile  west  of;  2 
\p  ised;  inferior. 
ittonville,  2  mile.-  Qortheasl  of.  on  road  to  Fisher,  at  top  of  rise;  bed  under  light 
cover. 
Strattonville,  '1  miles  northeasl  of,  near  schoolhouse;  -mall  showing,  hut  clay  appar- 
ently of  excellenl  quality. 
('lav  workers  will  appreciate  the  difficulty  of  attempting  to  pro- 
nounce judgment  on  a  claj  from  a  field  examination  of  an  outcrop; 
()nl\  such  comments  are  made  on  the  outcrops  above  noted  as  are 
obviously  justified,  the  object  being  to  call  the  attention  of  those  who 
are  interested  to  the  occurrences  of  promising  clay  beds. 
Upper  Freeport  7iori2on.  -Present  indications  do  not  show  that  the 
Hint  clay  from  'he  upper  Freeport  horizon  is  important.  Note  was 
made,  however,  of  the  following  occurrences  of  this  clay: 
Rimersburg,  I  mile  north  of.  a1  road  fork;  good  outcrop  near  top  of  hill. 
Piollett,  l  mile  west  of ;  fragments  al  top  of  hill. 
tburg,  2  mih-  southeasl  of,  mi  ridge  road;  fragments. 
Truittsburg,  '_'  miles  northeast  of;  outcrop  of  inferior  quality. 
COMMERCIAL  DEVELOPMENT. 
At  present  there  are  three  clay-working  plants  in  the  quadrangle, 
viz.  the  Canton  Tile  Hollow  Brick  Company,  the  Hawthorn  Pottery 
Company,  and  the  Sligo  Fire  Brick  Company,  the  character  of  whose 
product-  has  already  been  stated.  In  the  future  development  of  the 
clays  of  t  he  quadrangle  t  he  Hint  clay  from  the  Lower  Kittanning  hori- 
zon seems  to  offer  the  greatest  possibilit  ies.  Alt  hough  t  his  clay  is  not 
equal  in  quality  to  the  best  (lint  clay-  on  the  market  it  nevertheless 
makes  a  fairly  good  lire  brick.  The  w  liter  does  not  know  that  experi- 
ments have  been  made  in  the  use  of  plastic  clay  from  the  same  horizon 
as  a  bond,  but  observation  of  outcrops  indicates  that  if  the  clay  were 
to  be  used  on  the  spot  the  plastic  clay  accompanying  the  flint  at  most 
places  would  be  sufficient,  in  quant  it y  at  least .  to  furnish  the  necessary 
bond. 
