THE NONMETALLIC MINERALS. 439 



2. EXHIBIT ILLUSTRATING VARIATION IN COLOR. 



The series may be divided into two portions, beginning with a thor- 

 oughly black specimen and following through increasing amounts of 

 green and red to a light greenish yellow in the first portion, and in 

 the second beginning with a dark red and following through to a light 

 straw, in which the greenish element of the color does not appear: 



(1) Black. Bear Creek, Burkesville, Cumberland County, Kentucky. (59832.) 



(2) Black, tinged with green. Mecca, Trumbull County, Ohio. (59757.) 



(3) Dark greenish. Anchor well No. 3, Glade, Warren County, Pennsylvania. 

 (59761.) 



(4) Dark greenish red. Dale Brothers' well No. 1, Batten farm, near Rockland, 

 Venango County, Pennsylvania. (59767. ) 



(5) Dark greenish red. Kane, Armstrong County, Pennsylvania. (59752.) 



(6) Light greenish red. Gordon well, Washington, Washington County, Penn- 

 sylvania. (59526.) 



(7) Greenish yellow. Leedecker well, Butler County, Pennsylvania. (59750.) 



(8) Dark red. New Brinker well, Pleasant Valley, Westmoreland County, Penn- 

 sylvania, (59520. ) 



(9) Light red. Galtz well, Washington, Washington County, Pennsylvania. 

 (59527.) 



(10) Amber. Hess, Sacket & Eichner well No. 1, Reklsburgh, Clarion County, 

 Pennsylvania. (59581.) 



(11) Yellow. Riggs Gas well, Moundsville, Marshall County, West Virginia. 

 (59579.) 



(12) Light yellow. Farm of J. Somerville, near Brady's Bend, Armstrong County, 

 Pennsylvania. (59494.) 



(13) Light straw. Holden Run, Armstrong County, Pennsylvania. (53516.) 



(14) Nearly colorless. Venezuela. (59835. ) 



3. EXHIBIT ILLUSTRATING GEOLOGICAL DISTRIBUTION. 



The series is arranged in a generally descending order. There is a 

 certain amount of overlapping, however, between the West Virginia 

 and Pennsylvania series, since the oil-bearing strata in these two States 

 have not been correlated. 



(1) From the Tertiary sandstone. Dark greenish. Pico district, Los Angeles 

 County, California. (59552.) 



(2) From the Cretaceous formation. Dark greenish. Canon City, Fremont County, 

 Colorado. (59548.) 



The following thirteen specimens are from the West Virginia oil 

 field. Their location in depth is referred to the Crinoidal limestone as 

 a datum line: 



(1) 50 feet above the Crinoidal limestone. Black; specific gravity 28 Baume. 

 Oil in sand; depth of well 56 feet; drilled 1859; not torpedoed; yielded 100 barrels of 

 oil on first day of pumping. Well No. 1, Dutton farm, Aurelius, Washington County, 

 Ohio. (59855. ) 



(2) 100 feet below the Crinoidal limestone. Dark greenish. Oil in sand; depth 

 of well 150 feet; drilled 1882; torpedoed; yielded 10 barrels of oil on first day of 

 pumping. Farm of Frank Atkinson, Aurelius, Washington County, Ohio. (59854.) 



