December 26, 1902. J 



SCIENCE. 



1029 



siiuilarly being uncovered of the Red Beds, 

 which are tliere probably Permian. These 

 two groups thus represent very ancient hills, 

 preserved to us through burial, and exhib- 

 iting, as they are now uncovered, topographic 

 features of Cambrian and Carboniferous 

 dates, respectively. Although Silurian and 

 earlier strata surrounding the Wichitas are 

 folded and overthrust, and although there are 

 some evidences of compression in the strata 

 dipping away from the Black Hills, the eleva- 

 tion in these cases, as in that of the St. 

 Francis Mountains, is apparently due rather 

 to vertical than to horizontal stress. Each 

 of the domes appears to stand for the local 

 effect of a vertical movement, such as that 

 which in the Appalachian province has raised 

 the Cretaceous peneplain to the height of the 

 Appalachian Mountains; and the internal 

 structures may be discriminated as effects of 

 earlier deformation. The comparison of the 

 three uplifts brings out the fact that similar 

 effects of vertical movement have been pro- 

 duced at intervals from Cambrian to Tertiary ; 

 and the nature of the growths bears interest- 

 ingly on the problem of the cause of such 

 local upward swelling. 



' Stratigraphic Relations of the Red Beds 

 to the Carboniferous and Permian in North- 

 ern Texas,' by Geo. I. Adams. This paper 

 reported the results of a reconnaissance made 

 for the purpose of reviewing the mapping 

 done by Mr. Cummins of the Texas Survey. 

 It was found that the limestones of the 

 Albany division, although they thin out 

 northward, extend across the line drawn as 

 the contact between the Carboniferous and 

 the Permian, and are represented in the Clear 

 Fork and Wichita divisions. The approxi- 

 mate limit of the red color is a line diagonal 

 to the strike of the formations and is found 

 to correspond in a general way with the line 

 drawn by Mr. Cummins as separating the 

 Carboniferous and Permian. The vertebrate 

 fossils from the Clear Fork and Wichita 

 divisions which have been referred to Per- 

 mian, are now known to belong to the Albany 

 which was classed as Carboniferous by the 

 Texas Survey. 



' Volcanic Dust from Guatemala,' by J. S. 



Diller. Mr. J. S. Diller presented specimens 

 of volcanic sand and dust received through 

 the U. S. Weather Bureau and the Chamber 

 of Commerce, San Diego, Cal., from the re- 

 cent eruption of Santa Maria in Guatemala. 

 The dust is remarkable for its light color and 

 feldspathic character. Ferromagnesian sili- 

 cates are subordinate and the glass particles 

 are very clear, as in dusts from volcanoes 

 erupting trachytes or rhyolites. 



One sample collected October 25 on the 

 deck of the steamer Luxor while in the harbor 

 of San Benito, Mexico, sixty miles from the 

 volcano, is uniformly fine sand with particles 

 nearly a millimeter in diameter. The par- 

 ticles are chiefly feldspar, of which only a 

 small part show distinct lamellar twinning. 

 The mineral grains are generally coated with 

 clear vesicular glass. 



The other sample collected on the deck of 

 the same vessel October 26, 200 miles from 

 the volcano, is much finer, like flour, and 

 composed predominantly of glass particles 

 ranging about .15 mm. in diameter. A chem- 

 ical examination of the coarser material will 

 soon be made. Alfeed IT. Brooks, 



Secretary. 



AMERICAN CHEMICAL SOCIETY, NORTHEASTERN 

 SECTION. 



The regular meeting of the Northeastern 

 Section of the American Chemical Society 

 was held Saturday, November 29, at Room 22 

 Walker Building, Massachusetts Institute of 

 Technology. 



Mr. Francis Fitz Gerald, of the Interna- 

 tional Graphite Company of Niagara Falls, 

 addressed the society on ' The Acheson Fur- 

 nace and its Products,' describing the pro- 

 cesses and apparatus used by the company 

 in the manufacture of carborundum and 



The following officers for the ensuing year 

 were elected : 



President, Augustus H. Gill. 



Vice-President, Henry Howard. 



Secretary, Arthur M. Comey. 



Treasurer, B. F. Davenport. 



Executive Commitiee, R. P. Williams, G. P. 

 Baxter, B. S. Merigold, H. C. Lythgoe, Henry 

 Fay. 



