388 
Indian Forest Records. 
[VOL. I. 
found that a possibility by number of trees will under existing con- 
ditions in India more nearly meet all present requirements. It will 
only be necessary therefore to briefly indicate the various volumet- 
ric methods of calculating the possibility, which may from time to 
time And an application in India. These various methods may be 
classifled as follows : — 
(i) Masson’s or Von Mantel’s Method. 
(ii) The Trench Method. 
(iii) Fellings limited by proportionate volume. 
(iv) Gurnaud’s Method. 
i. — Masson's or Von Mantel’s Method. 
The possibility under Masson’s Method is calculated by the use 
of the following formula : — 
Annual yield growing stock of the forest 
Half the number of years in the rotation 
This formula is based upon the idea that the real yield must bear the 
same proportion to the real growing stock as that existing between the 
normal yield and the normal growing stock.* That is — 
Real yield : Real growing stock I'. Normal yield : Normal growing 
stock. 
.-.Real yield = :Real Gi'owing Stock x 
But Normal Growing Stock = Normal Yield x 
rotation 
Real Yield= Real Growing Stock x 
Normal Yield 
Normal Yield x rotation ' 
Real Growing 
Stock 
rotation 
This method was applied in calculating the yield for the Naini 
Tal Municipal forests, and from that working plant the following 
extracts are taken : — 
The forests form a convenient working circle of 1,640 acres. 
The area dealt with has been divided into 27 compartments. In forming 
these compartments natural features have been taken as boundaries, and the 
composition of the forest growth has been considered. 
The compartments have been examined and described in detail. Two types 
of forest lands have been recognised : class A (coloured blue on the map), con- 
sisting of weU or fairly well stocked forest, in which trees of all ages are present. 
• See Schlich’s Manual of Forestry, Vol. Ill, pages 320 and 323. 
Working Plan of the Naini Tal Municipal forests, Naini Tal Division, 
United Provinces, by F. B. Bryant, I.F.S., 1895. 
