101. 



DETERMINATIOX OF THE INCREMENT 



conditions in Southern and Central England, will be found in 

 Appendix III. There is no pretence on the part of the Author 

 to maintain, that the tables absolutely apply to the conditions 

 found in the United Kingdom, but there is sufficient proof to 

 show, that the data given in them hold good approximately for 

 woods in the south and centre of England, and that they may 

 safely be used, until tables have been prepared based on data 

 collected in this country. It maj' be said, that the most 

 urgent need of British forestry is the collection of statistics, 



Yield Table for the Scotch Pine, I. Quality. 

 Derived from the Curves ia Figs. 35, 36, 37 and 38. 



by means of which the financial results of the industry can be 

 estimated. Until such statistics become available, no sub- 

 stantial progress is likely to be made, unless the results 

 obtained elsewhere are temporarily admitted. 



//. — Determination of the Increment of "Woods by Means 

 of Yield Tables. 



If yield tables are available, and it is desired to estimate the 

 increment of a wood forward or backward, it is necessaiy to 

 decide in the first place, which of the quality classes of the 

 tal)les corresponds with that of the given wood ; in other 



