[5] 



DIRECTIONS FOE COLLECTING ROCKS — MERRILL. 



METHOD OF COLLECTUSTG AND TRIMMING. 



With the heavier hammer knock off from the larger mass, by a single 

 blow if possible, a spall as near the size and shape of the desired hand- 



FiG. 6. 



Fig. 7. 

 Properly trimmed baud specimen. Fig. 6, end view. Fig. 7, face view. 



specimen as is possible. About four by five inches with a thickness not 

 above one inch is a very desirable form. The advantage of a single blow 



