COLLAPSE OF RECENT BEDS AT STAUNTON 39 



which later completely disappeared is seen in PI. III. The major 

 part of one of the foundation walls of a house occupied by Mr. 

 Todd went down with this break. PI. V shows the character of the 

 crevice in the limestone into which the engulfed materials dis- 

 appeared as seen under the Todd house. For a short time after 

 the caving began no water could be seen in the chasm but it rose 

 gradually until, at the time of the writer's visit, it stood within 

 23 feet of the surface of ground, or almost at the top of the limestone 

 channel seen in PL IV. The rate of inflow into this and the 

 adjacent "cave-ins" (PI. I), Nos. i and 2, is estimated at 40 gallons 

 per minute by Hon. J. Yost. The depth of the cavern into which 

 the superficial deposits have slumped has been shown by sounding 

 to be at one point at least 150 feet. 



With the development of the third chasm caving ceased, save for 

 occasional slumping of the walls, for more than two weeks. On 

 August 27, however, a fourth opening appeared on the opposite 

 side of Lewis street from the third hole, on the grounds of Mr.Yost. 

 This hole was cistern-shaped, from 10 to 12 feet in diameter and 18 

 deep. Still later an artificial excavation about 20 feet in width was 

 made by the city across Lewis street over the line of the crevice 

 opening into the cavern below for the purpose of arching it. Except 

 for the slumping of one of the sides of this excavation in which a 

 workman lost his life, no caving has occurred since that of 

 August 27. 



The openings in the streets have been filled in after archl g the 

 walls of the limestone crevice leading to the cavern below with 

 concrete. On the property of Mr. Yost a cement arch was extended 

 the entire length of the area disturbed by the caving. The work 

 on the Yost property was accomplished without any surface excava- 

 tion, it being carried out by tunneling over the line of the limestone 

 crevice from the base of a shaft. This was sunk on the inner side 

 of the "cave-in" on the Yost property to a depth of 44 feet. The 

 excavation showed the limestone walls to be separated by an aver- 

 age width of 3 to 4 feet, the space narrowing downwards. This 

 space was filled by tough, red clay. The width of the open interval 

 between the limestone walls in hole No. 3 (PI. I) is evidently much 

 greater than this if we judge from the size of the trees and house 

 which were engulfed. The only "cave-in" which still remains open 



