THE LANDSLIDES OF MT. GREYLOCK AND 

 BRIGGSVILLE, MASS. 



A study of the topographic and geologic maps of Mt. Grey- 

 lock will show where, theoretically, landslides would be most 

 likely to occur. Both the large and small slides on this moun- 

 tain are where, in theory, they should be. These slides are 

 typical of one class, and the one at Briggsville of another. 



The scarring of the mountain side by this agency is a very 

 striking feature of the landscape, as one looks west from the 

 Hoosac range and from the Hoosic valley for two or three 

 miles on either side of Adams. The eastern side of Greylock is 

 the steepest on the mountain, rising 1400 feet in two-fifths of a 

 mile. It was on this slope, the base of which is about two miles 

 west of Adams, that the land slipped. In all there are three 

 large and eight small landslides within a mile. 



The facts concerning the conditions at the time at which the 

 landslides occurred were gathered largely from persons in the 

 vicinity of Adams, but especially from Mr. C. O. Gould, whose 

 farm is located at the foot of the main slide. The facts are as 

 follows : During July and August, previous to August 20, 1901, 

 the date on which the slides occurred, 12.92 inches of rain fell, 

 being 5.8 inches above normal. At about three o'clock on the 

 afternoon of the 20th a very heavy rain, spoken of usually as a 

 cloudburst, began to fall, and lasted until seven o'clock. The 

 record for this period at Williamstown (on the other side of the 

 mountain) is 2 inches; at Mt. Tom, 3.42 inches. The water in 

 the creek at the foot of the mountain rose very rapidly until it 

 was as high as it had ever been noticed. When the slide 

 occurred the stream became "a torrent 75 to 100 feet wide, 10 

 feet deep, and filled with trees." Five or six acres of the farm 

 were covered with sand and bowlders, some of the bowlders 

 being 4 feet in diameter. 



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