336 



Bulletin 256. 



Fig. 257. — A method of re-establish- 

 ing a valtiabJe specimen — through 

 the grafting by approach of young 

 saplings of the same species. 



much harm; as the tree grows and expands in diameter, such bands 

 tighten, causing the bark to be broken and resulting after a few years 



in a partial girdling (Fig. 258). 



To bolt a tree correctly is compara- 

 tively inexpensive. The safest method 

 consists in passing a strong bolt through 

 a hole bored in the branch for this 

 purpose, and fastening it on the out- 

 side by means of a washer and a nut. 

 Generally the washer has been placed 

 against the bark and the nut then 

 holds it in place. A better method of 

 bolting, and one which insures a neat 

 appearance of the 

 branch in addi- 

 tion to serving as 

 the most certain 

 safeguard against 

 the entrance of 

 disease, is to 

 countersink the 

 nut in the bark and imbed it in portland cement 

 (Fig. 259). The hole for the sinking of the nut 

 and washer is thickly coated with lead paint and 

 then with a layer of cement on which are placed 

 the nut and washer, both of which are then im- 

 bedded in cement. If the outer surface of the 

 nut be flush with the plane of the bark, within a few years it will be 



covered by the growing tissue. 



The inner ends of the rods in the two branches 

 may be connected by a rod or chain. The pref- 



(^ C .!. fr " /f^ erence for the chain over the rod attachment 

 >— ''^ w/////y///7///'y^\ . , , , . , ., 



is based on the compressive and tensile stresses 



which come on the connection during wind 

 stonns. Rod connections arc preferred, however, 

 Fig. 259. — Care should when rigidity is required, as in unions made close 

 be e^^rcised in seeing ^^ ^^^^ ^^^^^^ ^^^ ^^^ ^^^. ^^^^ branches to- 

 that the bolls are prop- ' - ° 



erly inserted. gether before they have shown signs of weak- 



ening at the fork, the chain may best be used, 

 as the point of attachment may be placed some distance from the crotch, 

 where the flexiVnlity factor will be important and the strain comipara- 



FiG. 258. — Undesirable 

 methods of bracing 

 shade trees. 



