THI': CAVES AND POTHOLES AT ROCKWOOD. 249 



by 6 and 12 feet deep ; ISTo. 5, 8 feet by 4| and 8 feet deep ; No. 6, 

 6 feet by 6 and 10 feet deep ; No. 7, 12 feet by and 3 feet deep ; 

 No. 1, 20 feet by 15 and 30| feet deep, from the highest side to the 

 bottom and Ul from the lowest. 



These holes in the rock have usually a greater diameter about half 

 way down. The following measurements of No. 1 will show this : — 

 Four feet from the bottom, 2 1 1 Ijy 18 feet ; midway, 23 5-6ths by 19^> 

 feet; six feet from the top, 25 by 19| feet. Generally speaking the 

 outline of a vertical section is oval. 



Holes 2 and 6 are on the edge of the rock, and consequently are 

 somewhat imperfect ; from 5, which comes near the edge, there is a 

 small hole, which opens into the valley ; this enabled us to empty it 

 and learn the nature of its contents. At tirst we were desirous to 

 investigate the contents of No. 1, and with that view dug for the 

 first day, and returned to continue the woi'k. Much soil, fragments 

 of rock, etc., were dug up and wheeled away, but we found no trace 

 of rounded stones. After several hours of hard work, it was resolved 

 to proceed to the series in the valley and explore some there. 



The facilities for working at the large hole are good, inasmuch as 

 the material could be loaded into the wheelbarrow at the bottom, and 

 wheeled away a sliort distance and emptied into the ravine a few feet 

 below. 



We proceeded to No. 5 and entered upon the work of cleaning it 

 out ; only a few spadefuls of earth were taken out when some stones 

 were found, whose rounded shape had a wonderful inspiring effect 

 upon the workers. 



They were very round, and were of an entirely different composi- 

 tion from the solid rock in which the hole had been excavated. 



After some two hours digging the bottom was reached and a fine 

 collection, about two pailfuls, of rounded stones was obtained, varying 

 from 6 inches in diameter to half an inch. Many of the small stones 

 were as I'ound as marbles. 



These sixteen before you represent some typical forms, and will 

 enable you to form an idea of the interesting nature of these stones, 

 whose very appearance suggest questions as to how they came to be 

 so round, and how they got where they were found 1 



