300 



Royal Society 



During this period traces of man's skill would probably be left 

 within his miserable abode ; pottery, if he possessed the art ; char- 

 coal or charred wood, if he were acquainted with fire ; rude cutting 

 instruments of fliut or other hard stone, perhaps spear or arrow-heads. 



Fig. 4 represents the caverns at the end of the fourth period. 

 Fig. 4. 



5th Period. — Torrents entering by the aperture at C, might now 

 have swept through the upper cavern, perhaps at successive intervals 

 of time. The effect of such torrents would be to wash from the 

 sloping floor of the upper cavern, the mixed remains of animal and 

 human life, together with the earliest traces of human art. 



In some of these catastrophes, the workman, as well as his work, 

 may have been entombed together in the lower cavern. 

 Fig. 5. 



Thus in the course of time the whole of the lower cavern may 

 have been filled up even to the roof. 

 This state is represented in fig. .5. 



