Mineralogy and Geology. 433 
peak of Fogo is 2790 meters in height. It stands in the centre of a 
basaltic crater, rising 1000 meters above its base. The enclosing walls 
exterid entire half way around so as to forma semi-circular crest. On 
the broken side there are numerous scoria cones thrown up at the 
eruptions of 1785 to 1799, when all that flank of the island was 
covered with lavas. 
tr. Deville gives many particulars with reference to the island, 
and presented to the Geological Society of France a topographical 
chart of it. 
11. Notice of ah Example of apparent Drift Furrows dependent on 
Structure; by C. B. Apams, State Geologist of Vermont, &c. &c., 
(communicated for this Journal.)—The attention of geologists having 
been lately called to the question, whether the grooves and striz com- 
monly attributed to drift agency may not be due to structure,* it may not 
improper, in anticipation of the results of the survey of Vermont, to 
mention an example in which this is undoubtedly the case. Mr. Macin- 
tosh, the author of the article which is alluded to, and which was read 
before the Geological Society of London, particularly suggests that such 
may be the origin of the examples in the United States described by 
_ President Hitchcock, a suggestion, we will venture to add, which must 
We occasioned much surprise in those who are familiar with these 
effects of drift agency in the New England States, unless they also 
may have met with facts of the same nature with those which are the 
of this brief notice. 
ot far from the geographical centre of Vermont, in the town of 
_tt is proper to add that the examination of several hundred examples 
of tounded, smoothed, striated and furrowed rocks has brought to light 
only this case, in which structural grooves bear any resemblance to 
those which have resulted solely from an external mechanical force. 
i@ suggestion of Mr. Macintosh is therefore plainly incapable of 
8eneral or even common application, although cases may occur in 
Loraine ee EE 
Ri 8e® this Journal, ii Ser., Vol. i, p. 2773 and Sir R. I. Murehison’s Geology of 
Bee and the Ural Mountains, Vol. i, p. 566. 
ECOND Serigs, Vol. Ill, No. 9.—May, 1847. 55 
