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 
