626 STEVENSON— FORMATION OF COAL BEDS. [November 3. 



mained suspended in the Flume. That huge mass has never been 

 found. Yet, aside from a landsHde or two, the terrific rainfall left 

 the vegetation on the steep slopes unscarred. In June of 1903, a 

 cloudburst of unusual severity broke on the northern part of the 

 White mountains. The roads were gullied and rendered impassable ; 

 bridges, large and small, were swept away throughout the region as 

 the streams were filled beyond the high water mark of spring 

 freshets ; sheets of water poured down naked rock surfaces in many 

 portions of the abrupt spaces and landslides of limited extent were 

 produced where the slope was covered with loose material. But this 

 vast flood of water did practically no injury to the forest-covered 

 slopes; even debris left on the mountain side by tree-choppers was 

 almost undisturbed.^ 



But the most noteworthy evidence in this region is found on the 

 areas wdiich have been burned over. When a forest fire destroys 

 the soil near the top of a divide or on a very abrupt slope, the 

 residue is removed quickly by rain and the granite is exposed. But 

 if the organic matter has not been destroyed, the soil resists ordinary 

 rains even on steep slopes. If drenching rains be delayed for a few 

 weeks, the surface gains a cover of fireweed {Erechtitcs hieraci- 

 folia) and rain is powerless. This growth is succeeded in the fol- 

 lowing season by a dense cover of raspberry, fern and other plants, 

 among which a cherry takes root to become the characteristic form 

 in the third season. Birches, maples and poplars are prominent 

 during the next season and within five years the spruces make their 

 appearance. If drenching rains follow quickly after a forest fire, 

 the process of restoration is merely retarded, it is not prevented. 



Glenn*^ studied the problem throughout the southern Appa- 

 lachians, an area of 400 by 150 miles, and his studies were extended 

 to another area farther north, 200 by 50 miles. The examination 

 was continued westward for a long distance down the Tennessee 

 river, so that the investigation embraced every type from the bold 



° Communicated by C. A. Snell of Maiden, Mass., who examined the 

 whole area within four days after the disaster occurred. 



" L. C. Glenn, " Denudation and Erosion in the Southern Appalachian 

 Region," U. S. Geol. Survey, Professional Paper, y2, 191 1, pp. 15-18, 23, 24, 

 59, 93, 96, 99. 



]24 



