Lisi 
tance, beyond the place where the sewer crosses Highland street, 
the eruptive rock occurred in the bottom of the trench and was 
dug into only to a depth of some two feet. It was overlaid by 
nearly three feet of decomposed peridotite, which had been entire- 
ly changed to a soft greenish-yellow earth. As the excavation 
progressed to the east of Highland street, the workmen pene- 
trated deeper into the rock, which for some distance presented a 
slightly stratified appearance suggesting a sheet branching from 
the dike proper, which subsequent excavations proved to be the 
case. 
The dike itself was first encountered 126 feet east of the cen- 
ter of Highland street, and was so hard and firm as to be removed 
with great difficulty. The width of the dike is 36 feet and it 
comes up to within ten feet of the natural surface. From its loca- 
tion in the trench, which was five feet in width, the strike of the 
dike appeared to be N. 5 degrees E. There was scarcely any 
sheet to the east of the dike, but to the westward it extended over 
three hundred feet. 
The rock in the main dike, with the exception of the upper 
two feet, is perfectly hard and firm. It is of a dark green color, 
some of it being almost black, and contains an abundance of 
apparently jet black crystals. The upper portion, immediately 
beneath the drift, had changed to a soft greenish-yellow earth, 
in some places to a yellowish earth. The fact that the lower por- 
tion of the drift contained much of the serpentinous earth mixed 
with it would suggest that a considerable area was covered with 
eruptive matter. The typical rock contained few inclusions as 
compared with that at Dewitt, N. Y., or even that in the Syra- 
cuse dikes at Green street. The softer rock of the sheet, however, 
contained many of them. No prominent fossils were found in 
any of these inclusions, whereas in the rock at Dewitt they were 
very abundant. No traces of the enclosing walls of the dike 
could be found. Sheet material banked it on the west, and heavy 
pleistocene clays with quicksand beyond them formed the eastern 
border. At Green street the enclosing walls are perfectly shown, 
and it was hoped that further excavations would open up other 
exposures showing the contact phenomena, but this did not occur. 
