CHAPTER XVII. 



MEASUREMENTS FOR PURPOSES OF FOREST MANAGEMENT. 



THE ordinary method of measuring standing timber has been 

 dealt with in another chapter. 



But, for certain investigations into the growth of crops 

 where large areas have to be measured and great accuracy is 

 required, the ordinary method is not suitable; for it would 

 require a very great deal of time, and, moreover, the actual 

 height of the tree is more or less of an uncertainty. 



Continental foresters adopt another method. It is very 

 much quicker, and insures greater accuracy ; and, where a 

 large area under timber is being measured, their usual custom 

 is to assess the total true mathematical contents measured 

 over bark, including, also, branch wood. 



It will be instructive to note their methods of measuring 

 standing trees or whole crops of timber, as, to a great degree, 

 their methods will be found indispensable in this country, 

 when making scientific investigations ; although quarter girth 

 measurements should usually be adopted instead of true con- 

 tents measurements. 



Now, the true contents of standing timber are found by 

 multiplying together, the exact height, the basal area at 

 breast high, and the form factor. 



The exact height of standing trees may be found by the 

 use of various height measures, of which an instrument known 

 as Brandit's Hypsometer is, perhaps, the best. It is some- 

 what like a miniature telescope containing a dial with angles 

 marked upon it. This dial is pivoted and can be released 

 by pressing a button ; and becomes again fixed when the 



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