TIMBER ESTIMATING. 89 



i 



An attempt should not be made to apply this system of tall}^ ing 

 only 1 tree in 5 or 10 to narrow strips, where only a small per cent 

 of the stand is counted. On a 4-rod strip, the diameters of all 

 trees should be tallied. But where at least 5 percent, and pref- 

 erably 10 per cent, of the stand is actually recorded it is seldom 

 necessary to go further and tally the diameters or heights of 50 

 per cent. 



The chief merit of the method is that it enables a cruiser to 

 cover his territory more thoroughly, and at the same time avoid 

 the necessity of guessing at the average heights or volumes of the 

 counted trees. 



• ACCURATE PLOT SURVEYS. 



In certain scientific work it is necessary to determine accurately 

 the contents of sample plots as, for example, in the studies of 

 growth and in the determination of the future yield of forests. 

 Inasmuch as the average woodsman does not have occasion to make 

 such studies, the various methods of determination of the volume 

 of stands is not included in this work. 



THE CHOICE OF METHODS FOR ESTIMATING. 



For inexperienced men who have not the training necessary to 

 enable them to use ocular methods and judgment, there are but 

 two plans available for estimating timber. First, the 4-rod strip 

 or valuation survey, where the diameters are calipered and heights 

 measured with an instrument and the volumes obtained from a 



^volume table. Second, a modification of this in the form of plots 

 laid out systematically at definite distances on a compass course 

 with all of the trees carefully measured and their volumes computed 

 by volume table. Either of these systems is applicable anywhere 

 in any kind of timber, but the accuracy of the results will depend 

 on the soundness of the timber, care in elimination of dead and 

 worthless trees, per cent of total area covered, accuracy of the 

 volume table used, care with which differences or types in the 

 stands are distinguished, judgment in selecting for measurement 

 average heights with the hypsometer, and care in observing the 

 width of the strip. 



Foresters or cruisers with training and ability to use ocular 



^methods, when working alone, will obtain best results by using 



