These tables bring out a number of very interesting primary facts:

1. The rate of interest demanded of the investment is one of the
most important factors. This is because such long terms are involved.
The charges compound with prodigious rapidity toward the last.
In any other business paying 6 per cent, compound, the maximum
investment per acre given in the preceding table, that of a land
value of $7.50 and a 30-cent annual charge for 80 years, would
earn $1,317. A 75-year forest then harvestable should have 56-1/2
M to the acre, but this would have to bring over $25 per M to pay
as well. On the other hand, the same deposits earning 4 per cent
would only amount to $338 in the same period which would be equaled
by timber at $6 per M.

2. For similar reasons, the length of time before cutting has much
to do with profit or loss. The compounding of carrying charges
eventually outstrips the production of material to a degree which
can be offset only by the most rapid rise of stumpage values.

3. The greater the investment, the more marked the above effect and
consequently the tendency to market an inferior product. A 60-year
rotation is indicated by a majority of the conditions shown.

4. A comparatively slight increase in annual tax or fire charges
may make the difference between profit and loss. Roughly, stumpage
must bring $1 per M more to compensate for each 10 cents an acre
for taxes at 5 per cent or for 7 cents at 6 per cent.

5. If the land is salable for $5 an acre or more it cannot be made to
pay 6 per cent compound interest under the most favorable conditions,