394 Scientific Intelligence. 



very low anticlinal at Erie and Fredonia parallel to Lake Erie. 

 Ohio has afforded large gas-wells only along anticlinals ; " Ken- 

 tucky, Illinois and West Virginia tell the same story." 



The subterranean gas-horizons in Washington County, Pa., are 

 stated to be three : the first, 900 feet below the Pittsburg coal, 

 the second 1,800 feet, the third 2,000 feet. The first is from the 

 conglomerate No. XII, about 200 feet above the Subcarboniferous 

 limestone, and the pressure of the gas seldom exceeds 300 pounds 

 to the square inch. The horizon is that of the first Venango oil- 

 sand, and is the " gas horizon par excellence of southwestern 

 Pennsylvania " — being that of " Beaver, Allegheny, Butler and 

 Westmoreland Counties," and of Wellsburg, West Virginia. 

 The sand-rock is identified by Orton with the Berea grit of Ohio. 

 The pressure in the Murraysville region (Westmoreland Co.) sel- 

 dom exceeds 650 pounds to the square inch. The wells at Erie, 

 which go down 600 to 700 feet, show a maximum pressure of only 

 40 to 50 pounds. 



In another paper in the same number of the Petroleum Age, 

 some of the advantages of gas for fuel are stated to be the follow- 

 ing : ranges and furnaces of dwelling houses and factories may 

 be lit up or extinguished in an instant ; a steady heat is secured 

 without attention ; and no ash or flying dust accompanies the 

 management. In one of the great factories of Pittsburg the 

 twenty-four boilers that used to require the care of eighteen men 

 day and night when coal was used, now need the care of only 

 two. Storage of fuel is avoided; furnaces last longer; sulphur 

 is not supplied from the fuel to injure the iron and steel produced. 

 " There is one exception — it cannot be used in cupolas." 



2. Volcano of Barren Island in the Bay of Bengal. — A de- 

 tailed description of the Barren Island volcanic cone by Mr. F. R. 

 Mallet, is contained in vol. xxi, Part 4 of the Memoirs of the 

 Geological Survey of India. The position and features of the 

 island have given it a prominent place in works on volcanos. 

 This island has a diameter of two miles, the cone of about one. 



The outer slopes of lava rise to a height of about 1100 feet, at 

 an angle of nearly 25°, but are broken through to within 100 feet 

 of the sea-level on the west side. The interior is a great amphi- 

 theater, in which stands the central cone, 1,000 feet at summit 

 above tide level, whose sides have a surface of cinders or ash, and 

 an even slope of 32°. This angle may have been reduced since 

 the last ejection of cinders, by the rains which are heavy in this 

 region. The accompanying figure is a reduced copy of one of 

 the partially ideal sections illustrating Mr. Mallet's paper. 



Rugged bare lava streams, having a scoriaceous crust, almost 

 encircle the inner cone at its base ; and projections of lava at two 

 points high up the sides of the cone show that streams of lava have 



