X. 



FIG. 306— EXCAVATED, BOLTED AND CEMENTED CAVITIES 



A, Cross section of trunk showing new wood and bark f^rowing into unfille 

 ca\'ity from margin. Line on wood shows amount of excavating needed. B, Cross 

 "•eL-tion of cavity showing way to use single-headed bolt and nails where little or no 

 undercutting. C, Cross section of trunk, showing single-headed holts to brace 

 cavity. D, Oval washer showing best method of counter-sinking and bolting. 

 (Compare B and C.) E, Cross section of trunk in B cement filled. Cement sur- 

 face conforms to general shape of trunk and reaches only to cambium. 



