34G 
CEMENT MATERIALS AND INDUSTRY. 
[BULL. 
are worked at most of these points, differing in chemical compositioi 
as well as in geological age. Darton states a that at Rosendale th< 
lower bed, or dark cement rock, averages about 21 feet in thickness 
and the upper, or light cement rock, about 11 feet, the two cement bed; 
being here separated by 14 or 15 feet of worthless limestone. Th< 
lower bed lies directly on the Clinton quartzite, the even upper sur 
face of which affords an admirable floor for the galleries. For abou 
18 inches at the bottom the dark cement rock is too sandy for use 
With this exception, and a few small layers of chert, it is all available 
At Whiteport the upper bed is 12 feet thick and the lower 18 feet 
while they are separated by 17 to 20 feet of limestone. 
Analyses of natural-cement rock, Rosendale district, New York. 
Silica (Si0 2 ) 
Alumina (A1 2 3 ) 
Iron oxide (Fe 2 3 ) 
Lime (CaO) 
Magnesia (MgO) 
Alkalies (K 2 0,N%0) 
Sulphur trioxide (S() :i ) 
Carbon dioxide (C0 2 ) 
Water 
10.90 
3.40 
2.28 
29.57 
14. 04 
n. d. 
.01 
37. 90 
n. d. 
15.37 
9.13 
2.25 
25. 50 
12.35 
n. d. 
n.d. 
34.20 
1.20 
18.11 
4.64 
3.00 
24. 30 
14.26 
n. d. 
Trace. 
34.01 
n. d. 
18.76 
8.34 
1.85 
25.96 
11.00 
n. d. 
1.35 
32. 00 
n.d 
21.32 
7.39 
1.71 
23.75 
11.07 
n. d. 
1.90 
30.74 
n. d. 
21.41 
}l0. 09 
25.80 
10. 09 
n. d. 
.66 
30.93 
23. 80 
4.17 
4.71 
22.27 
12.09 
n.d. 
.90 
31. 00 
n.d. 
18. 5.' 
6.3' 
2.6: 
25. 3: 
12. Vi 
n.d 
.9( 
33.3: 
1. Lawrenceville. J. O. Hargrove, analyst. Letter to writer, October 4, 1900. 
2. Rondout. L. C Beck, analyst. Mineralogy of New York, p. 78. 
3-5. Lawrenceville. J. O. Hargrove, analyst. Letter. 
6. Rosendale district. C. Richardson, analyst. Brickbuilder, July, 1897. 
7. Lawrenceville. J. O. Hargrove, analyst. Letter. 
8. Average of preceding seven analyses. 
In the Rosendale district cylindrical kilns are used. These var} 
from 8 to 12 feet in diameter and from 20 to 36 feet in height. A 
kiln fed with one-half ton of anthracite, pea size, will give 75 to 8( 
barrels of cement a day. This is equivalent to a fuel consumption 
of about 7 per cent on the weight of cement produced. From one 
fifth to one- third of the total product of the kiln may be overburnec 
clinker or underburned rock. This item, however, depends largelj 
upon the skill of the burners, though it is also affected by uncontrolla- 
ble factors, such as temperature, weather conditions, force and direc- 
tion of the wind. 
aThirteenth Ann. Kept. X. Y. state Geologist, vol. 1, L894, p. 334. 
