REPORT OF THE DIRECTOR I915 99 



a couple of years later when the original marks, no doubt, were 

 more or less erased. However, his account clearly shows that it 

 was a typical case of the adjustment of an unbalanced load on a wet 

 substratum similar to that described as having occurred recently at 

 Hudson. 



The scene of the disturbance Avas on the farm of Casper Flans- 

 burgh, 4 miles north of Coxsackie and 2 miles back from the river, 

 along the bank of a small creek which is stated to have occupied 

 a ravine about 75 feet below the terrace level. The time of the 

 occurrence was in March, between 5 p. m. of the 15th and 9 a. m. 

 of the i6th. There was no frost in the ground. The more 

 important features are thus set forth in the original account : 



The mass of earth consisting of the slope of the west bank and 

 a part of the summit level, broke off sharply and perpendicularly 

 across the top of the bank about 30 or 40 feet back from the 

 brow ; the line of fracture then curved to the east on both sides until 

 it touched the creek, after inclosing a semicircular tract of about 

 6^ acres. The flexure seems to have been determined by small 

 ravines running toward the creek at right angles to its course. 



The fragment, which was in fact an enormous wedge of earth, 

 75 feet thick at the back, being now free, was at once subjected 

 to two different forces; for it was immediately separated into 

 two parts by a chasm opening lengthwise and stretching from end 

 to end (N. and S.), at the distance from the upper edge of about 

 one-third of the whole width of the detached mass. The portion 

 west of this line, consisting of the brow of the hill, and the higher 

 part of the slope, at once sunk, partially throughout its whole 

 extent, but most deeply at its western edge, which rested at a 

 depth of 40 feet below its former position at the terrace level ; it 

 probably moved also a few feet to the eastward. 



The other fragment also sunk considerably at its thicker end, 

 thus bringing its surface nearer to a level ; but it had also a decided 

 sliding movement toward the creek, for the distance of from a foot 

 or two at the southern, to 42 feet at the northern end. This 

 measurement was obtained by ascertaining the variation of a line of 

 stakes, trees and other landmarks, from the original line which 

 was known. 



The effect of this double movement upon the ground at the creek 

 was extraordinary; the whole bed of the stream, together with a 

 portion of its borders, was lifted bodily, and left at the top of a long 

 and nearly continuous mound. This mound is from 75 to 1-50 

 feet wide at the base, and in most places 30 feet high, thus becoming 

 the highest ground on the eastern section of the slide. 



It appears that blue clay came to, the surface on the outer edge 

 of the uplifted block. Of the sunken area a large part came down 



