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, unless the stumpage received exceeds $6. At $5 stumpage and with reasonable taxation it will pay 5 per cent if it escapes fire. 6. Thirty cents an acre is apparently about the maximum annual carrying charge which will permit a 6 per cent profit, even with very high stumpage prices. Consequently, while present taxes on cut-over land are seldom prohibitive, there must be reasonable certainty that excessive increase will not occur. The carrying charges shown in the second table cover both fire protection and taxes, as by reading the 15-cent line to include a 10-cent tax and a 5-cent fire patrol. The investment charge may be used to represent sale value only, or sale value plus any expense incurred at time of logging in order to secure reproduction, such as leaving salable material in seed trees, or planting. If desired, any owner may make a similar calculation on any other valuation better fitting his own situation. The table is not intended for universal use but merely as an illustration of how forest calculations may be made. WHITE PINE Too much space would be required to give a similar table for all western species, even were as good yield figures available. Roughly speaking, however, western white pine, under conditions thoroughly favorable to it, may be expected to make as good a yield as Douglas fir, and the above fir table will not be far off for it. A probably higher stumpage value should offset any lesser production. HEMLOCK