THE GENERAL WORKING SCHEME. 151 



produce. These latter cuttings must have their yield based on 

 area. By this we do not mean to say that Thinnings ought 

 necessarily to go over equal areas every year, or that such cuttings 

 ought to yield the same outturn year after year. Although "the 

 outturn of thinning operations is not entirely to be neglected, still 

 it cannot be taken into account in determining the annual yield, 

 since it is subject to too wide a fluctuation not only as regards 

 ■quantity but also the class and quality of the produce obtained. 

 Besides this, the principal and, so to say, sole object of Thinnings is 

 to favour the growth of the promising trees forming an organic 

 part of a canopied mass of forest, by giving those trees growing 

 room in proportion as they require it, by the gradual removal 

 of their less promising neighbours which prevent their crowns 

 from sprendiag out. These operations demand great skill 

 and caution, and in order that they may be well executed, the 

 Executive Officer must be free from all preoccupation as to the 

 quantity, to cut out ; and more than this, he must be in a position 

 to judge, at the time that he marks the trees to be thinned 

 out, when the next Thinning will have to be made over the same 

 area. This reason suffices of itself to justify the expediency of 

 making such cuttings within fixed limits marked out on the ground, 

 of subjecting them to a regular rotation, and of basing their yield 

 entirely on area. 



When these exploitations can be so arranged as to annually 

 pass over nearly equal areas during the term of a whole Period, 

 no more desirable result could be imagined. But at the very com- 

 mencement of working a forest according to some organised system, 

 it is not always possible to secure such great regularity. Thus, for 

 example, it may happen that a Thinning is urgently required in cer- 

 tain crops aggregating a large area ; under such circumstances, it 

 would be only at the second or third time of thinning those crops that 

 it would be possible to establish a regular rotation for the operation, 

 i. e. limit it to nearly equal annual areas by assigning to each year 

 either one or more entire compartments or an aliquot portion of a large 

 compartment, as the case may be. However it be, the main point to 

 adhere to is to arrange the Thinnings in the simplest manner pos- 

 sible, paying due attention to the condition of the crops and to the 

 superficies they occupy. 



