36 TREES OF THE NORTHERN UNITED STATES 
and B F G D shows the bark. The central pith is at I; 
the heart-wood extends from C to J; the sap-wood from 
J to D. The silver grain is well shown at the end, and 
the blotches formed by it on the radial section. 
By having the piece made smooth, and the upper part 
down to the center (H) varnished, the appearance of the 
wood in furniture or inside finish will be illustrated. 
The specimens should be as nearly uniform in size as 
possible. If a limb 8 inches in diameter be taken and a 
length of 6 inches be cut off, the section A B D C should 
pass through the line of pith; the section E F G should 
be parallel with this at a distance from it of two inches; 
and two inches from the line of pith, the section A E C 
should be made. The whole specimen will then be 6 
inches wide and long, and 2 inches thick. 
The twigs containing leaves, flowers and fruit need to 
be pressed while drying in order that they may be kept 
in good form and made tough enough to be retained as 
specimens, The plants should be placed between a large 
supply of newspapers, or, better still, untarred building- 
felt, while drying. A weight of from 40 to 80 pounds is 
needed to produce the requisite pressure. The weight is 
placed upon a board covering the pile of plants and paper. 
On account of the size of many leaves and flower-clusters, 
these pressed specimens of trees should not be shorter than 
from 12 to 15 inches, and even a length of 18 inches is an 
advantage. The pads or newspapers should be about 12 
by 18 inches. A transfer of the plants into dry pads each 
day for a few days will hasten the drying and increase 
the beauty of the specimens. The specimens of twigs can 
be mounted on cardboard by being partly pasted and 
parily secured by narrow strips of gummed cloth placed 
across the heavier portions. The cardboard should be 
uniform in size. One of the regular sizes of Bristol-board 
is 22 by 28 inches; this will cut into four pieces 11 by 14. 
Specimens not over 15 inches in length can readily be 
mounted on these, and for most collectors this might be 
