MEASURING THE FOREST CROP 109 



adapt his cruising methods to different regions and with 

 care attain results that are quite accurate. His methods, 

 however, require a small party of men and are likely 

 to be slower and more expensive than the cruiser who 

 generally works single-handed or with one man. 

 Between the two systems that of the trained forester 

 is more desirable; his efforts produce results in the 

 form of timber and topographic maps upon which are 

 shown the kinds of timber, past cuttings, best logging 

 values, etc., while the average cruiser's estimate is likely 

 to be a lump estimate. If a practical woodsman can 

 be taught systematic methods and to put his reports 

 in written form the ideal estimator may be obtained. 



Estimating Methods. The roughest way of estimating 

 timber is what is known as the ocular method and mil- 

 lions of dollars' worth of timber have been bought upon 

 such reports. By simply walking across a forty acre 

 subdivision a woodsman with good judgment can make 

 a good guess as to how much it contains. He may do 

 this unconsciously but in reality he is comparing the 

 tract with others which he has seen cut down and whose 

 yield he has known. 



Some practical cruisers have devised a scheme of 

 counting the trees on a strip of given width and by 

 knowing the contents of the average tree, the total 

 contents can be computed. 



The method of measuring the forest crop used by the 

 technically trained forester is based upon the plan of 

 measuring all the trees upon a certain fraction of the 

 forest, say one-tenth, and after computing the timber 

 contents of this strip the yield of the entire forest can 

 be obtained by simply multiplying this result by ten. It 

 is an approximation of course, for only by measuring 

 the diameter and height of every tree could the exact 



