On a Recent Diamond Find in Wisconsin. — Hobbs. 31 
the Klamath mountains, however, yet remains to be deter- 
mined. 
There are then probabl} r four important geological horizons 
represented in this section : Devonian, Carboniferous, Trias, 
and Jura; the fossils showing the rocks to be successively 
older from east to west. The structural relations of the dif- 
ferent horizons yet remain to be worked out. Whether un- 
conformities exist is not yet known. It would appear that 
the region of greatest upheaval and disturbance lay to the 
west; that structurally the Klamath mountains are more dis- 
tinct from the Sierra Nevada than has been supposed. 
There is yet no proof of any granite or other crystalline 
rock in this region older than the sedimentary complex. The 
hornblende granite near the Fisheries, referred to by Becker 
and White as older than the sandstones underlying the Car- 
boniferous, is probably younger, as it is fine-grained near the 
edges and terminates in ramifying dike-like arms. The age 
of the most of the granite of the Klamath mountains is not 
known. That of one of the eastern ranges, the Trinity 
mountains, is probably post-Jurassic. 
ON A RECENT DIAMOND FIND IN WISCONSIN AND 
ON THE PROBABLE SOURCE OF THIS AND 
OTHER WISCONSIN DIAMONDS.* 
By William H. Hobbs, Madison, Wis. 
In October, 1893, a son of Charles Devine found sour- bright 
stones while playing in a clay bank on the farm of Judson 
Devine which is located near the village of Oregon in Dane 
county, Wisconsin. These stones lie took home and in Nov- 
ember of the same year they were brought to me for examin- 
ation. One of them proved to be a rough diamond, the others 
being quartz pebbles. The diamond is a slightly distorted 
rhombic dodecahedron with much rounded laces. It has an 
average diameter of about a quarter of an inch and weighs 
3.83 carats. It is not perfectly transparent, but the grayish 
coloring matter which it contains is apparently superficial. 
The edges of the rhombic dodecahedron seem to lie slightly 
*Read before the Wisconsin Academj "I' Sciences, Dec. 30th, 1893 
