THE MINING AND QUARRY INDUSTRY IQI2 89 
has caused much unfavorable comment. The tendency to rapid 
weathering which is announced by a roughening or pitting of the 
exposed surface seems to be inherent more especially in the mar- 
bles that have an even grain with the individual particles of square 
or rounded form. Such particles are not so well interlocked as 
those of prismatic shape. The weathering in most instances 
seems to be a mechanical process, simply a loosening of the bond 
through frost action or the expansion and contraction incident to 
changes of temperature. Normally, dolomite is harder and more 
resistent to the attack of solvents than calcium limestones. 
South Dover Marble Co. Of the developed quarries in this 
section, the principal one 1n current operation is that of the South 
Dover Marble Co., situated near Wingdale, Dutchess county, a 
station on the Harlem Railroad. The area of crystalline lime- 
stone or marble lies on the flanks of a broad gneiss ridge which 
extends north and south along the New York-Connecticut bound- 
ary. The limestone shows a flat or slightly undulating surface in 
contrast with the rugged contours of the gneiss country. The 
quarries are about 2 miles in a direct line northeast of Wingdale, 
but somewhat over that distance by road. They are connected 
with the mill at the station by an electric tramway over which the 
large quarry blocks are transferred for cutting. 
The company operates two quarries, the one being on the east 
slope of a low ridge facing the gneiss ridge and the second a little 
farther up the slope and northwest of the former. The lower 
_ quarry has an extreme length of 250 feet and a width of 150 feet 
in the southern half, but considerable less on the north. It is 
135 feet in extreme depth. There are three derricks in place. The 
other opening is 150 feet long, 75 feet wide and about 60 feet 
deep. It has two derricks and an overhead cableway, the latter 
serving to convey the waste to the dump. 
The marble is of medium texture, with prismatic and angular 
dolomite particles which measure from .75 to I mm. in diameter. 
It is practically pure white in color, and banding or veining is 
scarcely noticeable. The structure, as exhibited in the quarry 
walls, indicates an easterly dip of about 40° for the southern 
quarry and a westerly one of 50°-60° in the northern one, the 
reversal taking place in the distance of 100 feet. The marble is 
very compact, though in one place an open joint or water course 
extends to a depth of 50 feet. It shows slight exfoliation and 
weathering at the surface, with stained rock to a depth of 10 feet. 
