ir»S The A^imrxd II (itoJiK/isf. September, 18'Jl 
argumi'iit from soiuheast dip is farlluT shown to lie worthless 
from the fact that the white limestones are proved anticlines in 
structure as well as the blue. 
(b. ) The white limestones occupy axes of great disturbance as 
denoted l)y the intrusion of eruptive rocks; by excessive shatter- 
ing; by sudden and great disturbance of dip and strike. 
The force of this point will be more strongly felt if one ob- 
serves the isofttNiI patches of white limestone between Franklin 
Furnace and Andover. Here the blue limestones lie against the 
gneiss with numerous outcrops of sandstone. When there is an 
area of white limestone, it is not far removed from the blue, but 
it is accompanied Ijy great masses of granite and other eruptives 
and the sandstones are usually graphitic. 
2. The associated rocks. 
(a.) One of the strong ties which l)ind the two limestones to- 
gether is the sandstone. This sandstone is found so abundantly 
and at such critical points as to form an evidence quite as strong 
as the actual passage of the blue into the white limestone. 
These sandstones, in many places, form the axis of hills which 
are anticlinal in structure and which have one end of a flank blue 
limestone, and the other end white. These sandstones lie muJer 
the l)lue limestones and can be traced till they disappear muler 
the white limestone. 
These sandstones are graphitic when near either a white lime- 
stone or near a granite dike accompanied or unaccompanied by 
Avhite limestone. 
Prof. Dana is perfectly right when he says, '-evidence drawn 
from graphite is of uncertain value," but that is a general state- 
ment. In the case at hand the writer believes that the conditions 
under which the graphite occurs make its testimony not only 
strongly corroborative, but direct and positive. 
The presence of graphite in the blue limestone will be mentioned 
under 3. (b.) The w^iite limestones, as already stated, are 
characterized by eruptive rocks. The most characteristic of 
these is the granite. There is hardly an area of white lime- 
stone which is not accompanied by granite; even where gran- 
ite is not visible on the surface the white limestone is filled with 
intrusive sheets of it. This is proved by the drill borings. I.IOO 
feet deep at Franklin Furnace. There were eight holes in all, 
and each had successive layers of granite. 
