262 Dr. Hitchcock on some Phenomena of Drift. 
I ought to add that the rock of which these blocks consist, is of 
that intermediate kind which will be referred to different places 
in the geological scale by different geologists, according to their 
theoretical views. Nevertheless, it has a character so distinct that 
even a common observer would not mistake it or confound it with 
any of the rocks in place over which the blocks are strewed. 
The opinion that it is serpentine I consider quite untenable. 
The blocks composing the trains seem to be confined to the 
surface. We have a fine opportunity of seeing this where the 
main train crosses the western railroad. At that spot the road is 
excavated to a considerable depth into drift, that is rounded. But 
not one of these blocks is seen mixed with it. They lie only on 
the surface. Nor could I see any evidence on any of them, that 
they had been at all subject to attrition, Yet the hills over which 
they have passed are all smoothed and furrowed on their western 
_sides, and by a force acting in the same direction as that which 
conveyed these angular blocks; but they could not have been | 
concerned in the attrition, otherwise their angles would have 
been worn off. In short, it is certain that these blocks must 
have been transported in some very quiet manner to their present 
situation. Indeed, had they been blasted by human power, and 
conveyed by men to their places, and arranged carefully in lines, 
and then suffered to weather for a few centuries, they would ap- 
pear much as they now do. 
I have spoken of these trains as if they pursued an undeviating 
course. But I must now modify this statement. From their 
starting point to the middle of Richmond, I could discover no de- 
viation from a right line. But when we come into the broad val- 
ley lying between Richmond and Lenox Mountain, the direction 
changes about 30°. As far as Richmond, the course by the true 
meridian is E. 34° 8. From thence the remainder of the dis- 
tance, certainly to Lenox Mountain, it is E. 56° S. Possibly 
there may be another change of a few degrees beyond Lenox 
Mountain. This change in the course may be seen on the map, 
where the trains are shown by dotted lines. 
' The quantity of these blocks, taking the whole length of the 
trains into account, is immense. In some places they almost 
cover the ground ; as where we begin to ascend the hill to the 
northwest of Richmond meeting-house. In other places the in- 
terval between them is several rods. 
