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. 
