ECKEL.] 
NORTH DAKOTA. 
351 
burned cement rock. The clinkers which are no1 broken fine enough by the disin- 
tegrators to pass the screen are conveyed toia Griffin mill, where they arc ground to 
make "Portland" cement. 
Analyses of natural cements, Akron-Buffalo district, New York. 
Silica (Si() 2 ) 
Alumina (A1 2 3 ) 
Iron oxide (Fe 2 3 ) ... 
Lime (CaO) 
Magnesia ( MgO ) 
Alkalies (K 2 0, Na 2 0) . 
Carbon dioxide (C0 2 ). 
Water 
17.14 
7. HI 
2. 00 
36. 83 
25. 09 
3. 64 
n. d. 
n. d. 
4. 00 
22.70 22.62 
7.44 
7.40 ' 
36. 31 
25. 72 
n. d. 
1.40 
40. 68 
22. 00 
2.23 
3.63 
26.69 
7.21 
1.30 
43.12 
19.55 
1. 13 
1.00 
24. 30 
2.61 
6.20 
39. 45 
6. 16 
5. 30 
15.23 
26. 69 
7.21 
1.30 
53. 12 
9.55 
1. 13 
33. 80 
4.66 
52. 28 
9.26 
29.64 
6. 42 
54. 77 
9. 17 
22. 29 
7.32 
1.57 
39. 23 
23. 12 
2. 33 
2.88 
1. " Union Akron" brand. Haas and McGraw, analysts. Kn^ineering News, April 30, 1896. 
2. "Buffalo Portland" brand. Lord, analyst. Report Ohio Geological Survey, vol. 6, p. G74. 
3. "Newman Akron" brand. Quoted by Cummings. American Cements, p. 35. 
4. "Obelisk" brand. Quoted by Cummings. Ibid. 
5. "Buffalo Hydraulic" brand. " Quoted by Cummings. Ibid. 
6-8. Quoted by Uriah Cummings in letter to writer, January 30, 1901, as analyses of various cements 
made at Akron. Compare No. 6 with No. 4. 
). Average of analyses Nos. 1, 2, 3, and 4. 
NATURAL-CEMENT RESOURCES OF NORTH DAKOTA. 
The single natural-cement plant operating in this State is located 
about 10 miles east of Milton, Cavalier County. The rock used is a 
soft, chalky limestone of Cretaceous age, and outcrops in a bluff sev- 
eral hundred feet high. At present, however, only a 10-foot bed is 
being worked by mining. 
Analyses of natural cement, North Dakota. 
Silica (Si0 2 ) 
Alumina (A1 2 8 ) . . 
Iron oxide (Fe 2 3 ) 
Lime (CaO) 
1 
2 
8 
4 
5 
6 
7 
8 . 
24.62 
23.60 
23.90 
24.72 
24.40 
24.40 
24.06 
24.46 
}l5. 12 
16.50 
15. 90 
15. 00 
15.26 
15.38 
15.00 
15. 30 
52. 30 
51. 40 
51.40 
51.30 
52. 07 
51.96 
51. 96 
52.37 
1-8. Analyses of natural eement, Pembina Cement Company, Milton, N. Dak. 
9. Average of preceding eight analyses. 
At the Pembria plant a kiln 40 feet high and 10 feet in external 
diameter is used. The shell is of one-eighth-inch No. 14 boiler iron. 
The kiln space is broadest at the top, narrows down to a throat about 
6 feet in diameter, below which it again enlarges, reaching almost to 
the kiln shell at 15 feet above the base. Below this it is again some- 
