ACRIM OR TIMBER-GROWTH FIGURE, 9] 
The Forest Commission of the State of Maine, U.S.A., sketches thus the 
forestry procedure in the national forests :— 
A trained forester is in charge as a supervisor, and Forest Rangers are em- 
ployed. Tree-planting is practised where natural reproduction is not sufficient. 
Sales of timber are made under strict regulations. All trees to be removed are 
marked by a forest officer; and 12 in. in diameter, breast-high, is as small as soft 
timber may be cut. On account of the care given to them the forest lands become 
of great advantage to the State.—(F. H. Co.ry.) 
For the official instruction in marking a mixed forest of Pinus 
ponderosa, Douglas-fir, &c., in Oregon, see p. 122. 
It might be thought that marking and measuring timber before fell- 
ing would be a costly operation. This is not so. The rapidity with 
which a bushman in New Zealand gets about and recognizes the timber- 
trees is unsurpassed. In the Auckland District, where timber has been 
marked and measured before felling for some years, the average cost 
works out to almost exactly ld. per 100 sup. ft.—say, 0°ld. per cubie 
foot. 
THE TIMBER-YIELD AND REVENUE OF THE FOREST. 
ACRIM OR TIMBER-GROWTH FIGURE. 
Taking the forest through, there will be trees of all ages, either 
(1) mixed up together, as in the wild forest or jardinage forest, or 
(2) with the ages more or less graduated in separate compartments, as 
in the normal forest; and there will be a yield-figure (acrim) repre- 
senting the bulk of timber laid on yearly, which will gradually rise, 
reach a maximum in probably about eighty years (see published Yield 
Tables), and then gradually fall. Neglected thinnings would make it 
fall sooner and more rapidly. Then there is the acrim from two points 
of view: (1) The average acrim, taking in the whole age of the forest, and 
(2) the current acrim for short periods. Further, the acrim may be 
for the whole tree, or for the timber only. As soon as New Zealand 
gets town forests, or other accessible forests, it will be for, the whole tree, 
but at present the yield-figure for the whole tree has no practical signi- 
ficance. Here and elsewhere in this report I consider only the bole of 
the tree and the average timber acrim—viz., the average timber incre- 
ment per acre per year taken, unless otherwise stated, up to the cutting- 
period. This is near enough for a general discussion, and the corre- 
sponding current acrim or other acrim can easily be approximated from 
any of the published Yield Tables for forest with corresponding factors. 
The average timber acrim is shown in Schlich’s tables as ‘‘ Total yield, 
solid cubic feet, timber only, mean annual increment’’ (column §, 
p. 375, &e., vol. 3, of Schlich’s Manual). 
The average timber acrim here assumed for the normal Kauri forest 
of the future is 100 c. ft. q.g. of Kauri and 40 of other timbers, rising 
gradually as the forest improves to 200 c. ft. q.g. of Kauri (p. 101). The 
moderation of these figures will be seen by referring to the general Table 
of Acrims given in the statistical appendix. It will be noted also that 
a rough calculation made the Puhipuhi acrim about 175 c. ft. q.g. of 
Kauri (p. 63). Acrims are discussed in ‘‘ Australian Forestry’’ at 
pp. 123 and 401. 
Three general acrims may be mentioned here :— 
(1.) 95, the general figure for the whole State of Baden—practically 
the Black Forest. The soil here is poor, the climate rigorous; in fact, 
