110 The American Geologist. August, 1894 
rather educational and scientific. Too many of the state ex- 
hibits were prepared by gentlemen who eared only for the 
economic interests involved, and they got together large quan- 
tities of various Ores which confronted the visitor on every 
side ad nauseam. 
Adjoining the Massachusetts mineral exhibit was that of 
New York, which had all the variety and volume which mighl 
be expected from that state. One of the most striking objects 
here was a case of green lluorite from McComb, St. Lawrence 
county. In the collections of the New York State Cabinet 
was an obelisk made up under the direction of Mr. F. -I. H. 
Merrill, consisting of cut blocks from all the formations of the 
state, taken from quarries or other sections. It was thirty 
feet high and four feet square at the base. The cap and top 
course were of trap and Triassic sandstone, and the base of 
Archean granites and gneisses. The four sides of the column 
showed the occurrence of the formations in the respective 
quarters of the state, each formation being represented by one 
or more courses, according to its relative thickness. Above 
the Archean was the "Cambrian," which was divided into 
Georgian and Acadian, the Georgian being the thickest for- 
mation represented in the column, having six courses. The 
Acadian had two. The Hudson River, including the [Ttica 
slate, had five courses. The Potsdam was put at the base of 
the Lower Silurian and had one course. It did not cover the 
Calciferous, which also had one course. 
The magnetic iron ores from Orange, Essex and St. Law- 
rence counties, New York, and the Clinton red hematite were 
well represented; while in the gallery were 102 four-inch pol- 
ished cubes of the granites and other crystalline building 
stones. 
The Michigan exhibit of crystalline rocks was under the 
direction of Hon. Peter White, of Marquette, assisted by Jul- 
ius Roper and by others. Here was a drawing showing the 
geological succession through the iron districts of the Ish- 
peming basin, a distance north and south of over seven miles. 
This brought out the structural relations of the ore deposits 
and of the associated rocks. The formations concerned were 
represented by 50 or 60 rock samples. This was made by 
Julius Roper. There were also 720 specimens of the Archean 
