44 BULLETIN 24, U. S. DEPARTMENT OF AGRICULTURE. - 
inches in diameter, such as could usually be obtained from well- 
stocked stands of this age. The following figures are believed to be 
representative of such stands: 
Per cent. 
BBX ap-€] 0Y0Ys 0 0 | petae cee eae ae ae PN Sate BY Sa SE Sota Toa aig inte ar Sa lg 5 
Firsts and seconds__ x, £ SLE ee ree 18 
iNOS dcommon 6s Sis ee aa Ape (epee £40 ae ps leeed op 30 
INO.-2.cOMmMOon==s= =n ere tet eee oo eye Sy ae ee re FAG 
Prices for various grades will, of course, vary with the locality, 
season, or year. The following prices, which were fairly typical for 
the different grades f. 0. b. at the mill during the fall of 1912, are 
used as a basis to determine the relative log values for the several 
instances cited: 
Per thousand. 
Boxboards) =s222se spies Ske nent ety se ea ae heey. eo $44 
Firsts and seconds spt yl 8 ea eel is We eG) 
No. 1 common_____ e Let ara a Pe ee il 
INO>.2 Common === 2" SE AS SU Be ae URS Oh ade Pe aN 16 
Nos 3) common==== te meee nae NS Pre age ke RS Le uy 
Using these figures, the actual mill-run values per thousand feet 
for the instances cited are given in Table 9. 
TABLE 9.—Value of logs of different grades based on actual mill run. 
Range of : 
és logs, di- Mion 
Age. : values per | Stumpage. 
ameter M- | 1 900 feet 
side bark. 2 g 
Years. Inches. 
35 14-24 $20. 88 $5. 00 
46 14-30 21.96 6.08 
90 24-48 26.35 10.47 
Assuming that logging and milling costs are the same for the three 
ages cited, it appears that stumpage values will be apt to increase a 
little more than $1 per thousand between the ages of 35 and 46 years. 
By comparing the stumpage values given on page 42 it is evident 
that one can not afford to hold the timber, since the cost increases 
four times more than the stumpage value. The time for cutting 
cottonwood stands established to-day must eventually be determined 
on the basis of future market conditions. From the present indica- 
tions, however, a maximum of 35 years will be necessary for cotton- 
wood grown for saw timber in natural unthinned stands. In stands 
established artificially the same yields can probably be obtained in 
much shorter time, for the regular spacing in such stands enables the 
young trees to attain in four or five years the dimensions of six or 
» eight year old trees in dense natural thickets. Where thinnings are 
