88 
SLATE DEPOSITS AND INDUSTRY OF UNITED STATUS. 
Peach Bottom slate lias been thoroughly tested by Professor Merriman,« with 
results as follows: 
Modulus of rupture in pounds per square inch, LI. 260; ultimate deflection in 
inches on supports 22 inches apart, 0.293; specific gravity, 2.894; softness (grain! 
abraded by 50 turns of a small grindstone), 0.90; porosity (per cent- of water 
absorbed in twenty-four hours), 0.224; corrodibility (percent of weight lost- in sixty- 
three hours in acid solution, consist intr of 98 per cent 1 1.,( >, 1 per cent IK !1, 1 per cent 
0.226. 
The three published analyses show the following percentages of lime: 0.155,0 0.3, 
0. is."' Thai by the second State Survey will be found in full on page 34. (Anal 
VII.) This lime may be referable t<> the phosphate apatite, which the analyses 
show to be present. 
Peach Bottom slates are now used exclusively for roofing purposes. The chid 
features of this slate are stated in tabular form in the section on the comparative 
characteristics of slates (p. 124). 
TENNESSEE. 
By Edwin ( '. Eckel. 
Slate deposits occur in eastern Tennessee, notably southeast of Knoxville. The 
deposits here are described by Mr. Keith.' as follows: 
Two formations in this region contain beds of slate — the Wilhite and Pigeon lates. The WilhM 
• t :alcareous and Boft for commercial use in the vicinity of Little Tennessee River, bu1 has 
the accessary hardness, evenness, and cleavage along Little Pigeon River. A-long this stream tht 
slate is well exposed over great areas, but has oever been developed. Quarries have been opened ir 
the Pigeon slate along the Little Tennessee River a1 many points, and slates and flags taken out Efl 
local use. Recently a quarry has been opened on a small creek 2 miles from the river and much gofl 
male rial taken out for shipment. The slates are of fine, even grain, and split into slabs an inch thick 
of any desirable size, or into roofing slates. In this particular quarry the cleavage crosses the bm 
ding and produces ribbons in much of the slate. An old quarry about 2 miles north of this shows tin 
cleavage and bedding coincident, and flag dily loosened. Some of the slate 1 J 
ers contain pyrite, necessitating selection of the material for use. There are a greal number of avail 
able places for quarrying in the bluffs along the river and the adjacenl small streams on either side i 
That this slate resists weathering is amply proved by the high, sharp slate cliffs thai border the rive 
along most of its course. 
The following analyses of slate quarried by the Southern Slate Company at Mary 
ville, Blount County, were made by Mr. Gilbert McCulloch, of the University o 
Tennessee. 
Analyses of Tennessee roofing slate. 
1. 
2. 
1. 
-• 
Silica (SiO->) 
58. 15 
21.88 
6.04 
1.86 
.46 
59.00 
23.44 
6.28 
1.30 
.50 
Potash (K.,Oj 
1.60 
2.34 
.65 
6.66 
•_'.( 
Alumina ( AI2O3) 
Soda (Na..O) 
1.', 1 
Iron oxide (Fe.>0;) 
Sulphur trioxide (S0 3 ) 
Lime(CaO) 
4.1 
Magnesia (MgO) 
oOp. cit. 
bSecond Pennsylvania 1 teo] 
pp. 269, 270. 
'■ Anal, by Booth, Garrett, a 
d Merrill, G. P., Rocks, rock 
e Keith, Arthur, Knoxville 
.Survey R 
id Blair, 1 
weatherii 
olio; Geo 
ept. Progr 
885; see M 
g, and soi 
ogic Atlas 
sss for 1877, Vol. CCC, 1880; Ana 
d. Geol. Survey, vol. 2, 1^98, p. 
Is. L897, p. 229. 
U.S., folio 16 U.8. Geol. Surv 
l.l.yA.S. 
226. 
jy, 1895, p 
\le< !real , 
6. 
