33 



Second, to remove all decayed tissue, which is done by a thorough 

 cleaning out of the cavities. 



Third, to treat antiseptically all those exposed tissues which are 

 susceptible to decay, preventing further disintegration. 



Fourth, to fill the cavity with some substance such as cement or to 

 cover the surface with metal or other substance, in order that the 

 callus may grow over the cavity and form a smooth surface. 



Fifth, to strengthen the tree. This may follow immediately as a 

 result of filling, or ultimately in the processes of growth, and some- 

 times is not accomplished at all. 



Exposed tissues in cavities are treated with creosote or other sub- 

 stances to serve as an effective 

 antiseptic. The cavities are ' 

 filled with grouting composed 

 of one part of cement to five 

 parts of sand and gravel, over [\ 

 which is spread a coating one- 

 half to one inch thick of one 

 part of cement to two parts of 

 fine sand. The grouting should 

 be put in very soft, and the ce- 

 ment coating, which is put over 

 the surface, should be soft 

 enough to go on easily with a 

 trowel. The grouting is kept 

 back an inch or so from the 

 surface of the wood. It can be 

 held in place while soft by 

 boards loosely fitted to the 

 orifice of the cavity. „. cu • ^u j f i, • 



■' Fig. 13. Showing improper method of chain- 



Many unsatisfactory fillings '"« t^^^^- 1^°"*^^ "'"^^ ^^°^ '""•■« effective 



. method, b, bolt, c, chain. 



have been made by using the 



cement too dry, with the result that it possesses no strength. After 

 the cement has been put in the cavity it should be well trowelled 

 and kept moist for a few days. In all cases the cementing, when 

 complete, should be flush with the wood and the cavity so shaped, 

 when practicable, that it forms a wedge for the cement, thus pievent- 

 ins: it from falling: out. 



