302 Scientific Intelligence. 
the map. In the Catskill region the general direction of these 
flow and the main roads of th untry are made; the road from 
Kingston to Delhi being the principal exception. In going to the 
have long remained ignorant of its geological structure. 
mountains, where we have an elevation of nearly 4,000 — 
tide-water. The cause of this greater elevation is shown to 
“ : “69 : : f 
tion. To this condition we are indebted for the higher portions 
Schene- 
vus to Glasco, is on a line south of the culminating ridges, = 
t 
lower rocks of the section are of the Chemung Group * rom the 
a to Carbondale. Ch 
e lower beds shown, of Portage and Chemung, = tae 
ness of more than 2,000 feet; while the rocks above, ee y 
be referred to the Catskill, are about 3,000 feet. ee ad TOP; 
higher beds, of Vespertine, extending to the summit of Ro 
may be reckoned at about 800 feet.* sed 4,000 
* That the entire mountain elevation above tide-water does not ¢ less thaD 
feet, is due to the dip of the strata, which makes the elevation 80 much 
the thickness, 
have a tbick- 
