46 TREES OF THE NORTHERN UNITED STATES 



of the tree you wish to measure and, reaching up to 

 this height, pin a piece of white paper on the tree. Step 

 back a distance equal to three or four times the height 

 of the tree ; hold a lead-pencil upright between the 

 thumb and forefinger at arm's-length. Fix it so that 

 the end of the pencil shall be in line with the paper on 

 the trunk ; move the thumb down the pencil till it is in 

 line with the ground at the base of the tree ; move the 

 arm and pencil upward till the thumb is in line with 

 the paper, and note where the end of the pencil comes on 

 the tree. Again move the pencil till the thumb is in line 

 with the new position, and so continue the process till the 

 top of the tree is reached. The number of the measures 

 multiplied by the height you can reach will give quite 

 accurately the height of the tree. 



The width of the tree can be determined in the same 

 manner, the pencil, however, being held horizontally. 



In giving the forms of trees, it is well to accompany the 

 description with a penciled outline. 



The distance from the ground at which the trunk be- 

 gins to branch and the extent of the branching should 

 be noted. The direction taken by the branches, as well 

 as the regularity and the irregularity of their position, 

 should also be observed and described. 



Although most twigs are cylindrical, still there are 

 enough exceptions to make it necessary to examine them 

 with reference to their form. 



Under leaves, it will be well to make drawings, both of 

 the outline and of the veining. 



Crushed leaves will give the odor, and the sap can best 

 be noticed at the bases of young leaves. The differences 

 in sap and juice need the following words for their 

 description : watery, milky, mucilaginous, aromatic, spicy, 

 sweet, gummy, resinous. 



Pupils should not always be expected to find out much 

 about the flowers of a tree, as they are frequently very 

 evanescent, and usually difficult to reach. 



