eckel.] MARYLAND AND WEST VIRGINIA. 343 
1 Two types of kilns are in use in the Fort Scott district, Kansas. 
The more common type is cylindrical, 10 to 12 feet in diameter and 
(|30 to 40 feet in total height. The lower 10 feet or so is of stone, on 
which is set the kiln proper. This is constructed of one-sixteenth inch 
sheet iron, lined with successive layers of coal ashes, clay, common 
brick, and lire brick. These kilns are drawn daily, and yield 60 to 75 
barrels of cement each a day. The fuel used is slack coal, either 
Arkansas semibituminous from Poteau or Huntingdon or a very sul- 
phurous local coal which underlies the cement rock at Fort Scott. 
The coal is fed with the rock, and is used at the rate of 30 to 35 
pounds per barrel of cement, equal to a fuel consumption of 11.3 to 
13.2 per cent of the weight of cement produced. At a three-flame 
kiln the burning is managed by live men — two feeding and three draw- 
ing the kilns. 
At one of the Fort Scott plants four-flame kilns are also in use. 
These have separate fire places, so that the fuel and cement do not 
come into contact. Lump coal must be used for these kilns, and they 
are said to be more expensive, both in labor and fuel, than the type 
above described. 
Analysis of natural cements, Fort Scott, Kans. a 
Silica (Si0 2 ) * * 23. 32 
Alumina (Al 2 O s ) 6. 99 
Iron oxide ( Fe 2 3 ) 5. 97 
Lime (CaO) 53. 96 
Magnesia (MgO ) 7. 76 
Carl ton dioxide (C0 2 ) \ 9 ftn 
Water j 
NATURAL-CEMENT RESOURCES OF MARYLAND AND WEST 
VIRGINIA. 
The natural-cement industry of Maryland has been carried on in 
three separate areas. One of these areas includes the old plants at 
Antietam and Shepherdstown. The other two areas include respec- 
tively the plants at Cumberland and Potomac, in Allegany County, 
and that at Round Top, or Hancock, in Washington County. In both 
of these areas the limestones used are of the same geologic age and 
approximately of the same composition, so that they will be described 
together. 
In geologic age the natural-cement rock of the Cumberland-Hancock 
district corresponds closely to that used in the various New York dis- 
tricts, being assigned by geologists to the Salina group of the Silurian. 
It is a shaly limestone, varying in color from dark bluish gray to dull 
black. In the Cumberland area it is exposed in four beds of sufficient 
thickness to be worked, these cement beds being separated by shales 
and limestones. The separate beds vary from 6 to 17 feet in thickness. 
uBroekett's Double Star brand. Quoted by Cummings, American Cements, p. 35. 
