ECKEL.] 
AMERICAN    CEMENT    INDUSTRY. 
499 
In  such  States  as  have  but  a  single  plant  their  production  is  combined  with 
that  of  another  State,  in  order  that  the  separate  figures  <>f  any  plant  shall  not 
be  revealed.  In  the  table  above  the  Portland-cement  product  of  the  only  plant 
in  Alabama  which  produces  that  variety  of  cement  is  combined  with  the 
product  of  the  plants  in  Georgia,  Virginia,  and  West  Virginia.  The  plants  in 
Missouri  and  Arkansas  have  their  products  combined;  those  in  Kansas  and 
Texas,  and  those  in  Utah,  South  Dakota,  and  Colorado  also  show  combined 
products,  and  in  each  ease  the  result  is  given  in  connection  with  the  State 
which  was  the  largest  contributor  to  the  total  product. 
Production  <>f  the  Lehigh  district. — The  Portland- cement  produc- 
tion of  the  important  Lehigh  district  of  Pennsylvania-New  Jersey 
is  given  in  the  table  below  : 
Portland-cement  production  of  the  Lehigh   district,  1890-1903. 
Year. 
1890. 
1891 
1892. 
1893. 
1894. 
1895. 
1896. 
1897. 
| 1898. 
..,1899. 
fl|1900. 
Lehigh  district. 
Number 
of  plants. 
1901 
1902 
H903 
Number  of 
barrels. 
201,000 
248 , 500 
280. 840 
265.317 
485. 329 
634.276 
1,048,154 
2,002,059 
2,  674,  304 
4,110,132 
6, 153, 629 
8,595.34  b 
10,829,922 
12,324,922 
Entire  United  States. 
Number 
of  plants. 
17 
16 
19 
24 
22 
26 
29 
31 
36 
50 
56 
65 
71 
Number  of 
barrels. 
335, 500 
454, 813 
547, 440 
590. 652 
798.757 
990, 324 
1,543,023 
2, 677, 775 
3.(592,284 
5, 652, 266 
8,482,020 
12,711.225 
17, 230,  644 
22,342,973 
Value. 
$439,050 
1,067,429 
1,152,600 
1,158,138 
1,383,473 
1,586,830 
2,424.011 
4,315,891 
5.970,773 
8,074,371 
9, 280, 525 
12,532,360 
20, 864, 078 
27,713,319 
Percentage 
of  total  prod- 
uct manufac- 
tured in  Le- 
high district. 
60.0 
54.7 
51.3 
44.9 
60.8 
64.0 
68.1 
74.8 
72.  4 
72.7 
72.6 
67.7 
62.8 
r^.  l 
Production  from  various  raw  materials. — For  the  purposes  of  the 
present  section  it  will  be  sufficiently  accurate  to  consider  that  a  Port- 
pind-cement  mixture,  when  ready  for  burning,  will  consist  of  about 
1  T5  per  cent  of  lime  carbonate  (CaC03)  and  20  per  cent  of  silica 
](Si02),  alumina  (A1203),  and  iron  oxide  (  Fe.,()..)  together,  the 
Remaining  5  per  cent  including  any  magnesium  carbonate,  sulphur, 
Jirid  alkalis  that  may  be  present. 
The  essential  elements  which  enter  into  this  mixture — lime,  silica, 
Liumina,  and  iron — are  all  abundantly  and  widely  distributed  in 
Lature,  occurring  in  different  forms  in  many  kinds  of  work.  It  can 
herefore  readily  be  seen  that,  theoretically,  a  satisfactory  Portland- 
