702 REGINALD ALDWORTH DALY 
twelve miles in width. Since this occurrence covers more than 
four times as many square miles as any other, it may well be 
called the ‘‘ Main area.’’ Associated with it in Sullivan, Merri- 
mack, and Hillsboro counties, are some half dozen much smaller 
outcrops of the same rock which are surrounded by schists, and 
are thus outliers from the larger mass. Twelve miles west by 
south of Mount Monadnock, a second important mass of regular 
elliptical or oval-shape cuts cross the Ashuelot division of the Bos- 
ton and Maine railroad. The longer axis runs north and south, 
and is about ten miles long, while the shorter, transverse to the 
g, 
former, is six miles long. From the village of Ashuelot, situated 
on porphyritic granite, we shall derive a distinctive name, and 
call this the ‘‘ Ashuelot area.” The survey has mapped a large 
‘White Mountain area, 
ted form at the north of the Main area from Mount Stinson to 
”) 
which ts distributed in irregular elonga- 
Mount Lafayette. Some twenty miles long, it also varies con- 
siderably in width, being only a mile wide near the Profile 
House, but broadening out to six miles at the Kinsman Notch. 
From there a long tongue of the rock runs southerly down the 
valley of the Pemigewasset River. The strike of this area is 
like that of the Main area, a few degrees east of north. Follow- 
ing the common axis of both areas northward from the Profile 
House, a small but important ‘‘Littleton area” of some eight 
or ten square miles in extent, appears near the town of Littleton. 
The fourth widespread occurrence of the porphyritic granite is 
found in another irregular mass thirty miles long, and from one 
to eight broad, running parallel to the Main area from Laconia 
to Waterville. This may be referred to as the ‘‘ Winnipiseogee 
area,’ from its proximity to the beautiful lake of that name. 
The very local outcroppings of this rock in other parts of the 
state are in point of size insignificant, but they are of value in 
helping to determine the relations of the whole formation. Nota- 
ble among these are the small patch on the top of Mount Prospect 
west of Squam Lake and the long dikelike mass north of New 
Boston in Hillsboro county. The grounds for coloring in the 
mass of porphyritic granite at the southeast base of Mount 
