206 J. D. Dana—Taconic Rocks and Stratigraphy. 
a. The map and diagrams. 
The scale of the map is half an inch to the mile; and that 
of the plottings from which it has been reduced one and a half 
to two inches to the mile.* The limestone areas are the colored 
portions. The rocks of the uncolored areas are indicated in 
many parts by initials, as follows: 
M, ordinary mica schist, cHM, chloritic hydromica schist. 
eM, chloritic mica schist. Q, quartzyte. 
qM, quartzytic mica schist. mQ, micaceous quartzyte. 
stM, staurolitic mica schist. Gn, gneiss. 
HM, hydromica schist 
The rocks mQ and qM are intermediate between quartzyte 
sehi 
The strike and dip are indicated on the map by the T-shaped 
he positions of the ore-pits and quarries or workings are 
i i et closed 
e; aolin o os 
quartzyte, the rock quarried in the region for the hearthstom 
of furnaces. 
* The completion of unfinished work in the New York part, has led 0 
changes since the map in the last volume of this Journal (Plate III) was ae asl 
+ The heights stated on the map are in feet; and those along the railroa 
P 1996 feet, as his own etermination, and of Bear Mountain “" 
2250 feet. The height of Mount Everett, the highest summit of Mt. Was ingiom 
‘om the Massachusetts survey. 
