286 Scientific Intelligence, 
below as older than the Trenton limestone, and admits that they contain 
the characteristic Utica fossils; which, as Sir William Logan has shown, 
occur likewise on the north side of the island of Orleans. It is a man 
of the crystalline rock at the fall seems to cause Mr. Mareou no little 
perplexity. In 1860 he called it “quartzite passing into mica schist, 
gueissio? z : 
part of the crystalline rocks of the Laurentide mountains. We congrat- 
ulate Mr. Marcou that he is, little by little, admitting the orrectness of 
Sir William Logan’s original description of Montmorenci. 
But we must conclude this notice, which the opportunity afforded by 
it to discuss the interesting theme of the Taconic rocks, has led us to a4 
tract beyond the limits at first intended. The rocks of Vermont an 
Canada still require much study, before the details of their structure cal 
be fully known, but we think that it is evident that iu the red san 
and the lower black shales.we have the Primordial zone, of which “4 
original Potsdam sandstone is a member. These we believe to be, Wl 
the exception of the small Laurentian area, the oldest rocks of Vermont, 
nd we conceive that the whole series of Lower Taconic rocks, which Em- 
mons and Marcou place beneath these, will prove to belong to thes , 
fauna, if not in part to still newer rocks. So that Mr. Emmons claim 
for the Taconic, as a system of strata older than the Potsdam ag®, ' 
yet unsupported by any evidence. . 
[Nore 
.—In reference to certain charges of a personal nature — 
Y 
ne 
founded. The reference to Prof. Dana in the paper is also without a 
dation as he never saw the article referred to, owing to ill health, un 
months after it was printed.] 
III. ASTRONOMY AND METEOROLOGY. 
1, On the Companion of Sirius ; by Prof. G. P. Bonn, Director of i 
Observatory of Harvard College—The companion of Sirius, Regt . 
by Mr. Clark on the 31st of January, with his new achromatic © ed 
ee of eighteen and one-half inches aperture, I have succeeded 10 
serving with our refractor as follows: 
Angle of position, 85° 15! + 1%1 
Distance, 10” 37 ze 0"2 e 
The low altitude of Sirius in this latitude, even when on the eee 
makes it very difficult to catch sight of the companion, on acco it is 
atmospheric disturbances; when the images are tranquil, enti ee 
readily seen. It eat be regarded as the best possible od 
Superior quality « great object-glass, that it has served to © 
this minute star so close to the cnanenion brilliancy of Sirus. - 
