532 ARCHEOLOGICAL INVESTIGATIONS—II [ETH. ANN. 44 
stone in question, ranges in texture from nearly pure chalcedony and 
compact novaculite through millstone grit to a cellular condition 
almost like porous slag from a blast furnace. The color is mostly 
pure white; the closer grained varieties are sometimes translucent 
and tendon colored, while any of it may show here and there traces 
more or less marked of oxidized iron. Within an area of not quite 
2 acres the hillside seems to have been quarried in a methodical man- 
ner. The vertical range of the digging would indicate that frag- 
rents weathered from the outcrop, which had become imbedded in 
the clay several feet below their normal level, were as much desired 
as blocks broken directly from the ledge. The pits, trenches, and 
piles of débris are almost continuous within the given area, but cease 
abruptly at this hmit; and Doctor Whelpley has not been able to 
find a deposit of this particular material at any other place. 
Although only a very small percentage of it is sufficiently solid to be 
wrought into desired forms by any methods used by primitive arti- 
sans, many workshops have been located in the neighborhood where 
spalls and flakes occur in such abundance as to create serious doubt 
whether this one quarry site could furnish all the material used. The 
stone is susceptible of a high polish and of very delicate chipping. 
The finished implements range from ordinary arrows, spears, etc., 
to slender perforators 6 or 7 inches long; thin, wide blades; highly 
polished spuds, chisels, and picks, almost or quite a foot in length; 
and large notched hoes of the Mill Creek pattern. Possibly still 
other forms have been found. 
So far as could be ascertained, three collectors have monopolized 
and exhausted the output of these factories; namely, Doctor Whelp- 
ley, whose extensive and varied museum (it deserves the name) came 
into possession of his son and forms the basis of the remarkable 
“Whelpley collection” of St. Louis; Perrine, of Anna, whose entire 
collection was destroyed by fire; and Farrell, of Cobden, who sold at 
random wherever he could find a buyer. 
The Illinois Geological Survey calls all the siliceous rocks in this 
county by the comprehensive name of chert, and states that it occurs 
in all the formations from the Cambrian to the Carboniferous. ‘The 
dip of the strata is very unequal within small distances, being as 
much as 30 degrees from the horizontal at one place near the Missis- 
sippi River. The geological horizon of the quarries described could 
not be accurately determined in these researches; but they appear to 
extend through the Silurian, Devonian, and Lower Carboniferous. 
Fuint Near Apron, Ix. 
At the upper end of Alton, within the corporate limits, the Missis- 
sippi River cuts in against the foot of the hill, forming a vertical 
