782 JOURNAL OF FORESTRY 



the height is usually obtained with Christens hypsometer, the growth 

 rings are got by boring. The thickness of the bark, form class, and 

 other details are also noted down. The sample trees are never felled 

 in the regular estimating. This occurs only in the more special in- 

 vestigations. 



A crew generally consists of one leader and mapper, one compass 

 man, two caliper men, two chainmen, and often also a recorder of 

 sample trees. Thus eight men in all — a formidable array from an 

 American standpoint — are employed. The chainmen and caliper men, 

 however, can be of a cheaper class of labor. In this way they run 

 about five miles of line in a day on the average, every phase of the 

 work thus going on simultaneously. 



The strips run out from parallel bases lying about 400 to 1,500 

 meters apart. One point that impressed me in this respect was that 

 in all laying out of bases and control lines, trigonometrical methods 

 are invariably conspicuous by their absence ; they do not seem to even 

 dare use any but right-angle methods in their work. 



The woods are classified according to age or maturity (see further 

 on, under Government regulations for cut computations). Observa- 

 tions are recorded on the extent of damage, the effect of previous silvi- 

 cultural or other treatment, and the condition or presence of artificial 

 reforestation or natural growth, etc. 



Site quality is somewhat standardized for the whole of Sweden and 

 is based on the "wood-producing power" of the site when occupied by 

 its most suitable tree species. Thus the best quality can only occur in 

 the south where climatic conditions are most favorable. Jonson has 

 tried to standardize the numbering of site quality — the old production 

 figures being but slightly altered. His system is in general use. 



Normal density is indicated by the number 1, when the stand is 

 considered as using the ground to its best advantage, decimals over 

 and less than 1 indicate, respectively, the need of thinning or a more 

 open stand. 



The volumes are of course given in cubic meters of stem wood, 

 and are now almost invariably determined indirectly by the form 

 quotient and Jonson's tables, or even from felled sample trees taken 

 before or after the survey and from which volume tables are compiled ; 

 the average height and diameter referring each stand to its particular 

 volume table. This is quite correct considering the fact that for each 

 region the form class variations seem to follow height variations 



