MINERAL-PAINT    ORES    OF    LEHIGH    GAP,  PA. 
437 
The  roasted  ore  is  crushed  to  about  quarter-inch  size  in  a  Mosser  pot 
crusher  and  then  pulverized  by  millstones.  The  latter  are  of  several 
types.  At  a  plant  at  Bowman's  five  of  the  six  stones  in  use  were 
French  buhrs;  the  other  was  a  vertical  rock-emery  mill.  At  the 
Lehigh  Gap  plant  all  of  the  seven  mills  were  rock-emery.  Four  of 
them  were  horizontal  under  runner  stones;  the  other  three  were  ver- 
tical. It  is  generally  assumed  that  six  sets  of  stones  will  handle  the 
product  from  one  kiln. 
Character  of  the  product. — The  composition  of  the  metallic  paint 
from  this  district  is  fairly  indicated  by  the  following  analyses: 
Analyses  vf  finished  metallic  paint,  Lehigh  Gap  district,  Pennsylvania. 
Silica  (Si02) 37.  20 
Alumina  ( A1,03) .- 9.  60 
iron  oxide  (Fe203) 43.30 
Manganese  oxide  (MnO) 35 
Lime  (CaO) 10 
Magnesia  (MgO) 3. 35 
Sulphur  trioxide  (S03) 2.  38 
Phosphorus  pentoxide  (P205) 17 
Carbon  dioxide  and  organic  matter  (C02) 2.  40 
Water 60 
Metallic  iron  (Fe) 30.  30 
Sulphur  (S) .  95 
2. 
3. 
37.20 
35.30 
9.40 
10.70 
42.70 
43.  30 
1.40 
1.83 
1.70 
2.00 
1.70 
1 .  9  1 
1.S8 
1.95 
.  14 
.15 
2.60 
1 .  50 
.  60 
.90 
29.  90 
30.  30 
.7r» 
.78 
37.79 
10.  (il 
41.28 
1.27 
3.00 
2.  03 
1.94 
.  11 
2.  68 
28.90 
.77 
Analyses  1,2,  3  furnished  by  Mr.  Thompson,  president  Prince  Metallic  Paint  Company;  analysis  4 
quoted" from  Ann.  Rept.  Pennsylvania  Geol.  Survey  for  1886. 
The  paint  made  in  this  district  is  a  browner  red  than  that  made  from 
the  oolitic  red  hematites  at  Franklin,  N.  Y.,  and  Chattanooga,  Tenn. 
It  is  used  mostly  for  car  and  other  structural  work,  very  little  being 
used  as  mortar  color. 
Until  quite  recently  the  standard  package  for  this  paint  was  a  300- 
pound  barrel,  but  now  the  larger  consumers  (ear  shops,  etc.)  prefer  a 
500-pound  barrel.  A  portion  of  the  product  is  packed  in  100-pound 
kegs. 
