236 T. W. Harris — Mount Bob or Mount Ida. 



and the results were unsatisfactory. Samples of air were 

 taken at the bottom but could not be analyzed in time for use. 



A series of observations in a coal mine near the well gave as 

 a very probable value of the temperature of the top invariable 

 stratum 51°*3 F. From the mean annual temperature of 

 Marietta and Steuben ville it might be taken at 51° '5 F.* 

 Drilling is temporarily stopped, but we hope to go 5500 or 

 6000 feet. Mr. Amton Reyman of the Development Company 

 has generously guaranteed half the expenses and we are wait- 

 ing for a lucky man to furnish the other $3000, and enable the 

 Wheeling well to be lifted from the second to the first place 

 among the deep wells of the world. 



The gratitude of the scientific world is due to the Wheeling- 

 Development Co. who ordered and paid for the well, to T. S. 

 Kinsey who drilled it, and to Prof. I. C. White who discovered 

 it and induced its owners to dedicate it to science. 



Art. XXX. — Mount Bob, Mount Ma, or Snake Hill • by 

 T. W. Harris. 



When a series of stratified rocks, extending over a wide 

 area, is long exposed to the destructive activities of the 

 weather and other erosive agencies, it is gradually removed, 

 first along the courses of the principal streams, then along 

 their smaller branches, and finally, at a decreasing rate, from 

 the back country, on which, however, small scattered outliers 

 may long remain, marking the former extension of the now 

 almost destroyed formation. 



In eastern New York, a number of such small outliers mark 

 thus the former eastward extension of the Helderberg lime- 

 stones, nearly to the foot of the Berkshire Hills. Several of 

 these are mentioned by the State Geologists of New York. 

 Two, lying east of the Hudson River, near the city of Hud- 

 son, are given especial prominence by W. W. Mather, in the 

 volume of the Natural History of New York descriptive of 

 the Geology of the First District (Albany, 1842), under the 

 names, respectively, of Becraft's Mountain and Mount Bob. 

 The structure and relations of the former, have also been 

 fully described in this Journal (vol. xxvi, 1883, p. 381) by 

 Mr. W. M. Davis, of Cambridge. 



Sometime ago I visited the latter outlier, and found it to be 

 in general of similar character to Becraft's Mountain, as de- 

 scribed by Messrs. Mather and Davis, though of smaller area, 

 and simpler structure. Mr. Mather says of it — 



* As reduced by Chas. A. Sehott, TJ. S. Coast and Geodetic Survey. 



