Wooden biace for asphalt- 

 briquette Tvall 



156 PRACTICAL TREE REPAIR 



briquette wall and the rear wall of the cavity. 

 Or a little longer board can be built right into 

 the briquette wall, being nailed to the briquettes 

 and extending back far enough to touch the back 

 of the cavity. Such a brace can be made to resist 



a pulling as well as a 

 pushing force by nailing 

 to it a cross-piece fitted 

 into a part of the cavity 

 which is wider than the 

 mouth. 



It must not be sup- 

 posed, however, that 

 the asphalt wall is of 

 itself weak. On the contrary, it is very strong, 

 but the conditions surrounding work in trees are 

 so extremely trying that braces which may never 

 be called on to undergo an ounce of strain ought 

 to be put in, if only by way of insurance. 



The filling in the space back of the wall forms 

 a backing for the wall, helping to hold it in place. 

 The filling also helps in putting in some types of 

 braces and it holds them in place. On the whole, 

 I am inclined to consider coal ashes or fine cinders 

 the best material for filling the space back of the 

 briquette wall, on account of their packing qual- 

 ities, their cheapness, and the fact that they need 

 no treatment to make them proof against insects 

 and decay. 



