204 SCIENCE OF THE STUDY OF TREES. PART II. 
gram, as is done in fig. 2. The parallelogram suited for an octavo page 
is 4 in. broad, and 7 in. long; and the divisions are a fourth of an inch each. 
This parallelogram admits of a drawing of a tree 30 ft. high, with its branches 
extending over a space 16ft.in diameter. These dimensions may be con- 
sidered as the maximum for trees ten years planted, even under the most 
favourable circumstances; and therefore this size of page, and this scale, are 
what we have adopted for our Arboretum Britannicum. One page being 
marked as in fig. 2., all the other pages in the book, or any number of separate 
pages, may be marked in a similar manner by pricking through them from the 
different divisions of the scale. 
For the purpose of drawing full-grown trees within the limits of the same 
sized parallelogram, we assume 90 ft. as the maximum height of the tree, 
and 48 ft. as the maximum diameter of the space covered by the branches ; 
and, for this purpose, the same division of the inch into four parts will 
suffice, but with this difference, that each of these parts must now be con- 
sidered as 3ft., instead as of 1ft. J%g.2. is marked in this manner, in 
the inside of the parallelogram, for old trees; and it is marked in the 
manner before desbribed, on the outside of the parallelogram, for young trees. 
In practice, it is unnecessary to mark the figures, as the draughtsman will 
easily bearin recollection what each division represents. For trees exceeding 
90 ft. in height, and 48 ft. in width, the margin may be encroached on, to the 
extent of half an inch on each side, and at top and bottom, which will afford 
space for a tree 102 ft. high, and with a head 60 ft. in diameter. 
The draughtsman may now be considered as having got his directions, as 
far as respects paper and scale. Having prepared his pages, he will next pro- 
cure two black-lead pencils, one hard, and the other hard and black (tech- 
nically 4 and HB), together with afoot rule andachair. The next thing to be 
done is, to choose the tree and the aspect from which it is to be drawn. In 
making a choice, the average form, height and character of the species ought 
to be taken, as far as practicable ; and not a specimen remarkable either for 
its height, or for its singularity or peculiarity ; and the pomt from which it is 
to be drawn ought, if possible, to be on the south, south-east, or south-west 
side of it. The rule is, that the sun ought always to be behind the draughts- 
man, and rather to the left than to the right of him. All other circumstances 
being the same, therefore, when a tree is to be drawn in the morning, the 
draughtsman ought to place himself on the south-east side of it, at mid-day on 
the south side, and in the afternoon on the south-west side. The next point 
is, the distance from the tree at which the spectator ought to place himself. If 
he sits, which is, in general, the best mode, though some artists prefer a stand- 
ing posture when drawing, twice the height of the tree will be a very good 
distance ; but if he stands, and the tree has a very short trunk, say one under 
6 ft. in height, it will be advisable for the artist to add to his distance from the 
tree once, twice, or thrice his own height; otherwise the height of his eye 
above the lowest branches of the tree might cause the branches to conceal 
more of the trunk than’ would be desirable. It may be useful to add, that the 
principle on which the distance is chosen is that of being able to see the tree 
as a whole, or as an entire mass of light and shade easily comprehended by 
the eye fixed in one position, as opposed to that of seeing it in detail, and by 
changing the position of the eye. Experience has shown that the eye cannot 
comprehend more with ease than the fourth part of a circle, whether we take 
this circle as a vertical or as a horizontal plane, or as a solid globe, and imagine 
the eye in its centre. The principle which directs the position of the sun to 
be behind the spectator rather than in front of him, and at his left hand rather 
than at his right, is, that a portion of the tree may be in light, and another 
portion in shade, in order to show its general form and rotundity, and that the 
portion in shade may always be, for reasons to be hereafter given, on the 
right hand. In many cases, it may be necessary to draw the tree from the 
north side, and, in others, to draw it when the sun does not shine: in both 
