46 KERRY WOODS. 



Then the total present gross value of the whole area for forestry 

 purposes 2 V n . 



In the same way the sum of the present values of all expenses, 

 such as building's and roads not included in calculating the soil 

 expectation value, may be represented by 2E. 



Then the net value of the area for forestry purposes = 



If the value of the quantity (3 V n - 2E) be now reduced by some 

 factor (say 25 per cent.) as a margin against risks, a figure is 

 reached which approximates to the highest sum which can be given 

 for the whole of the land if the operations are to yield a minimum 

 return of 3 per cent, (in the present calculations) on all capital 

 invested. 



Calculations on these lines reduce the necessity for guesses and 

 the risk of loss to a minimum. The difficulty, as a rule, is to 

 estimate the soil expectation value owing to lack of reliable data 

 on tree growth. 



B. Systematic Method of Conducting a Survey. 



A systematic survey should proceed on the following lines : 



(1) Districts should be established corresponding as far as pos- 

 sible with the general conditions of forest growth. 



(2) The woods in each district should be visited, and the follow- 

 ing points noted : 



(a) Age and composition of the wood ; whether pure, 

 mixed, &c. 



(b) General condition of the wood and the probability of a 

 further detailed examination yielding useful data. 



(3) The woods noted under 2 (b) above should be examined with 

 special reference to aspect, elevation, volume per acre both 

 actually standing and under fully stocked conditions soil, &c. 



(4) The physical and chemical properties of the soil should be 

 examined where necessary. 



(5) The information collected should be correlated and analysed, 

 and the limits of profitable forestry determined : 



(a) As far as indicated by data gathered within the district. 



(b) As far as can be determined from data gathered out- 

 side the district, but reasonably applicable within it. 



(6) The district should be mapped for afforestation purposes, 

 the available area determined, and the economic side of the question 

 studied. 



C. Summary. 



The selection of land for afforestation may proceed on one of 

 two lines. 



(i) It can be taken for granted that afforestation will pay. The 



