322 
CEMENT MATERIALS AND INDUSTRY, 
[bull. 24 
here could obtain coal and ship its products over several lines 
Ordinarily coal could be had on the most favorable terms over tb 
Chesapeake and Ohio, but in times of labor disturbances in the Ne^ 
River field, coal could still be obtained from the Fairmont regior 
The Trenton limestones in the vicinity of Staunton as a rule ru 
unusually high in lime, so that it will be necessary to mix shales o 
clays with them. Unlimited quantities of shales occur with the Hint 
stones, but deposits of good clays are not so common. The shales i 
the lower part of these beds are unusually calcareous, as the followin 
analyses show, but those in the higher part of the series contain onl 
a very small percentage of lime. 
Analysis of sixties in the vicinity of Staunton, I 'a. 
[Charles Catlett, analyst.] 
Lime (CaO) 
Magnesia (MgO) 
Silica (Si0 2 ) 
Oxides (A1 2 3J Fe 2 3 ; 
Ignition (C0 2 ) 
35.87 
.94 
23.08 
10.08 
37.05 
1.72 
19.92 
10.76 
36.4 
l.(| 
19. S3 
9.S 
31.1 ] 
Lexington. — Lexington is favorably placed for cement manufacture 
for it is situated in the midst of a broad area of argillaceous lime 
stones. In this part of the valley the Trenton limestones have bee 
closely folded and overturned to the west, so that they show an extraor 
dinary thickness. Occasionally the core of an anticline or synclin 
may be noted, and whenever it is possible to make accurate measure 
ments the thickness of the limestones is found not to exceed 350 feel 
This rock is theoretically of proper composition to make a high-grad 
Portland cement, but, as noted by Catlett, it is a question whether th 
relatively high ratio of silica to iron and alumina, tending to increal 
the refractory character of the clinker, is offset by the finely divided cog 
dition and intimate mixing of the natural material. The followin 
analyses show variations in the composition of this rock. 
Analyses of Trenton limestone, Lexington, Va. 
[Charles Catlett, analyst.] 
Silica (Si0 2 ) 
Alumina ( A1 2 3 ) . . . 
Iron oxide (Fe 2 :s ) 
Lime (CaO) 
Magnesia (MgO)... 
Ignition 
0.73 
.79 
53.71 
.83 
9.31 
3.47 
46.30 
11.86 
1.76 
46.64 
.74 
38,82 
12.92 
3.88 
45.14 
1.37 
37.20 
17.42 
4.70 
42.44 
1.68 
35. 62 
22. ( 
7.| 
36.? 
l.f 
32. I 
