COMPUTATION OF VOLUME 51 



continue to be done. Care should he taken to test the tables used; 

 and tables based upon one height for each diameter should not be 

 applied to stands of taller or shorter timber. In emergency cases 

 the form factor can be used to adapt the table. 



European practice frequently uses the Draudt, or the Urich 

 methods, but in most state forests the ocular estimate is permissible, 

 and the use of Volume tables, like the old Bavarian tables is again 

 coming into favor. Where the Urich method is used, recent instruc- 

 tions, like the Bavarian of 1912, prescribe the felling of not less 

 than i c /c of the total stand for sample material to compute from. 

 ( )n a forty-acre lot with 6000 trees, this method calls for the felling 

 of sixty trees, to be worked up into the usual stuff and measured and 

 scaled. In Bavaria this is feasible in most localities, and readily 

 indicates not only the total volume but also the grades and with 

 this money value of the stand. In our country in localities remote 

 from mill and road, the sixty trees and all the labor of cutting would 

 be wasted. 



5. The Mapping. 



This, in good field work, is now done on a scale of 8", 12" and 

 even 16" to the mile. The work usually notes: land division, 

 topography, streams, roads, etc., forest types, burns, grazing and 

 waste lands. Clean work avoids crowding of material on sheet, 

 and especially the use of blunt crayon, etc., the ideal being a map 

 which can readily be copied by anyone. 



Topography in mountains is commonly taken with aneroid : 

 some form of "percenter" has advantages, especially in easy rolling 

 and relatively level country. 



6. Accuracy of the Work. 



In securing merely the amount of merchantable timber and 

 especially in old, defective timber, the experienced cruiser has ad- 

 vantage over a less experienced man, even with better methods. 

 Generally, however, this is not true, and the results of the forester's 

 work, using methods which can be planned, criticised, adapted to 

 conditions, checked at every step, and fully explained in court, 

 deserve the preference. Nevertheless one hears occasionally : "But 

 vou are not accurate, a bridge engineer can estimate the amount of 



