428 O. H. Landreth—Tramsit of Venus. 
Thus then, we have a connected series of deposits from 
-super-heated waters, their characters depending upon the com- 
position of these waters: 1. rue geysers the waters being 
ure alkaline carbonates deposit only silica. 2. At Steamboat 
prings there are some alkaline sulpbides, and, therefore, some 
metallic sulphides, but not enough to prevent a crust of depos- 
ited silica. 3. At the California Geysers—so-called—solfataric 
action is conspicuous and therefore no crust is formed, but only 
earthy residue of acid decomposition of surface rocks. Here 
we have also metallic sulphides deposited, but these are of little 
value. 4. At the cinnabar mines, near Steamboat Springs, we 
have solfataric waters depositing cinnabar and other metallic 
sulphides in considerable quantity, but whether in profitable 
quantity cannot be known certainly unless deeper explorations 
be undertaken. 5. Finally, at Sulphur Bank, the deposit of 
metallic sulphides is abundant and the formation of metallifer- 
-ous veins is illustrated in the most perfect manner on accoun 
of the deep explorations undertaken at this place. 
In connection with the idea so common, that the metals are 
‘derived immediately from igneous rocks, it may be well to 
draw attention to the fact, that igneous rocks are by far most 
abundant and igneous action most conspicuous at Yellowstone 
‘Geysers and at Steamboat Springs, where there are little or no 
metals; while at Sulphur Bank the country rocks beneath a 
depth of 20 to 80 feet are stratified sandstones and shales of 
‘Cretaceous age, the igneous rocks being very superficial and 
evidently contributing nothing to the metalliferous deposits. 
It would seem that igneous action supplies a necessary condition 
(heat) for the formation, rather than that igneous rocks supply 
the materials of metalliferous veins. 
Art. XLIV.— Observations of the Transit of Venus, Dec. 6th, 
1882, at the Vanderbilt University Observatory, Nashville, 
enn.; by Ouin H. LAnpReErs, Professor of Engineering; 
Vanderbilt University. 
By the courtesy of Dr. L. ©. Garland, Chancellor and Pro- 
fessor of Astronomy of this institution, in granting me the use 
-of the University Observatory during the Transit of Venus of 
Dec. 6th, 1882, I am enabled to make the following report of 
the observations and results obtained in connection therewith. 
given. ; 
Observations of external and internal ingress were wholly 
