THIRD REPORT OF THE DIRECTOR I906 49 



thirty feet from the beginning of the water this end of the cave 

 expands into a chamber at a higher level beyond which the passage 

 is small and so filled with water and soft clayey mud that it is 

 practically impassable. 



Section IV 

 Caves of the Helderberg mountain 



Several caverns exist at the base of the Manlius limestone 

 between Altamont and New Salem but because of the limited 

 area draining into them they have not developed to a size that 

 renders them accessible, and only one was found large enough 

 to enter. This is known as Sutphen's or Thacher's cave and is 

 on the property of Hon. John Boyd Thacher of Albany. It is 

 located at the base of the cliff beyond the alcove north of the Indian 

 Ladder road and is most conveniently reached by crossing the fields 

 back of the house occupied by Mr Albertus Hallenbeck or near 

 the top of the " Ladder." 



The passage for the first 530 feet is broad and low with pools 

 of water at intervals. The general direction of this first section 

 is n. 40° w. Then for 750 feet the cavern is a high narrow joint run- 

 ning n. 35° e. toward the face of the cliff. At the end of this sec- 

 tion the incongruous legend " farthest west " has been painted upon 

 the wall. The remainder of the cavern averages 2 feet in hight 

 and 12 in width, extending irregularly Vo the northwest for 1603 

 feet, beyond which it is impossible to go. A small branch which 

 leaves and returns to the main passage, something over 600 feet 

 from the farther end is clear of clay and fragments and high enough 

 to permit one to walk in a stooping position. For this reason it 

 was named " Comfort Loop," the comfort being purely relative. 



Thacher's cave probably receives its supply of water (which 

 is intermittent) from the area surrounding a depression i mile 

 northwest of its mouth. 



Wynn's cave and Livingston's cave near High Point, south of 

 Altamont are remnants of caverns whose streams were active before 

 the cliff had retreated to its present line. The former extends for 

 several rods, the latter is scarcely more than a room. 



These caves are all in the Coeymans-Manlius series. 



