ECKEL  ] 
AMERICAN    CEMENT    [NDTJSTEY. 
503 
Production  of  natural-rock  cement  in  1901,  1902,  and  1903,  by  States. 
1901. 
1902. 
1903. 
State. 
Num- 
ber of 
works. 
Quan- 
tity. 
Value. 
Num- 
ber of 
works. 
Quan- 
tity. 
Value. 
N  lim- 
ber of 
works. 
Quan- 
tity. 
Value. 
Georgia 
2 
2 
15 
"2 
4 
62 
1 
«18 
1 
d\ 
7 
1 
1 
1 
2 
Barrels. 
50.577 
169,842 
2,150,000 
175,560 
351,329 
L26,000 
$40, 96^ 
187,936 
752,500 
97,002 
175,0(15 
63,000 
3 
15 
2 
4 
o 
Barrels. 
55,535 
607,820 
1,727,146 
160,000 
409,200 
1511.  (l(  10 
$31,444 
156,855 
869,163 
80,000 
150,680 
67. 500 
2 
3 
15 
2 
4 
2 
Barrels. 
80,620 
543,  132 
1,533.5;:', 
220.293 
209,957 
L75,000 
$44, 402 
L78  900 
Indiana  and  Ken- 
tucky _ . . 
766  780 
Kansas 
169,155 
138,619 
78,750 
Maryland 
Minnesota 
Nebraska 
New  York ... 
North  Dakota 
2,234,131 
1,117,066 
19 
1 
2 
(5 
1 
2 
1 
2 
3.577,340 
2,135,036 
20 
1 
2 
2 
2 
1 
2 
2,417,137 
1,510,529 
Ohio 
L04,000 
942,364 
62, 4(H) 
376, 954 
67,025 
L,339,090 
46, 776 
Pennsylvania 
Texas. 
796,876 
340,669 
570, 209 
Virginia 
34,000 
88, 475 
437,913 
20,000 
62,655 
162, 628 
47,922 
25,901 
West  Virginia 
Wisconsin 
481,020       L82,788 
330,522 
139,373 
Total 
e&) 
7,084,823  3,056,278 
1 
/62  8,044,305 
4,076,630 
0  65 
7,030,271  3,675,520 
tori    lor 
that  of 
and 
Hi.-  h 
repoi 
1902. 
he  number 
tal  number 
ted  as  hav- 
other  State 
"  Includes  product  of  Nebraska  and  Texas. 
h  Includes  product  of  North  Dakota. 
c  The  number  of  companies  producing  natural  cement  only  i 
given  for  1899  and  1900  has  been  changed  accordingly,  as  in  tho 
of  companies  in  the  State  was  given. 
d  Includes  product  of  Virginia  and  West  Virginia. 
e  This  total  includes  one  plant  in  North  Dakota,  which  for  thi 
ine  a  natural-cement  product. 
'The  States  combined  for  1002  are  noted  in  the  text  of  the  re] 
"The  States  wherein  th'_«  product  of  cement  was  combined  with 
for  1903  are  given  in  the  text  below. 
The  single  cement  plant  in  North  Dakota  has  a  production  which 
for  1908  has  been  combined  with  that  of  the  only  plants  producing 
natural-rock  cement  in  Kansas  and  Texas.  The  other  States  stand  in 
the  table  exactly  as  the  reported  productions  are  given. 
PUZZOLAN   CEMENTS. 
The  term  '*  puzzolan  cements  "  is  applied  to  finely  ground  mix- 
tures of  slaked  Lime  with  certain  argillo-calcareous  materials.  These 
added  materials  may  be  either  natural  volcanic  products,  like  the 
pozzuolana,  trass,  and  santorin*  of  the  European  cement  trade,  or 
basic  slags  from  the  blast  furnace.  In  America  natural  puzzolanic 
materials  have  never  been  used,  though  they  are  known  to  exist  at 
various  points  in  the  West.  Slag,  however,  has  been  extensively  used 
in  the  manufacture  of  slag  cement. 
Slag  cement,  properly  so  called,  is  the  product  obtained  by  pul- 
verizing, without  calcination,  a  mixture  of  granulated  blast-furnace 
slag  and  slaked  lime.  This  product,  though  in  reality  a  member  of 
the  class  of  puzzolan  cements,  is  often  marketed  as  Portland  cement, 
in  spite  of  the  fact  that  it  differs  from  Portland  cements  in  method 
