COTTONWOOD IN THE MISSISSIPPI VALLEY. 48 
$13.88, respectively. Unless the owner were assured that the larger 
proportion of high grades cut from stands of these greater ages and - 
consequently larger average dimensions would give the standing 
“timber this large increase in value, he would not be justified in 
deferring the final cut. 
A determination of the rotation necessarily involves some knowl- 
edge of the manner in which an increase in the size of logs affects 
the proportion of different grades that can be cut from a given stand. 
One or two concrete examples will probably make this clear. For 
instance, one millman kept a detailed record of the grades sawed from 
certain logs representing the yield of a heavily stocked stand in north- 
western Mississippi cut clear in 1912. This stand was approximately 
46 years old, and the logs for the most part ranged from 14 to 30 
inches top diameter inside the bark. The following proportion of 
different grades, based on a two months’ cut of nearly half a million 
feet, is believed to be fairly typical of normally stocked pure stands: 
Per cent. 
BUSS COSXGED LENS UGS ees eee Pe SW he ee eee ee 9 
Firsts and seconds_______ eDEEES TEs R65 tpt sie JeNiee eo PEIN TS Bee miele 18 
INO scommon= ss Site at Sp Ai e Ee aie Ba 3 oe ae ce 30 
ENT OSS 2 CO TIMIN Oe eile ais Ae react Dea ee ROR. SS ee ee ee SEE 42 
INGOs. os COMMON = 2 ae DB Needs aes ile ede, Red comes 
In contrast to this is the actual mill tally for a run of unusually 
large logs from a stand supposed to be at least 90 years old. These 
high-grade logs ranged from 24 to 48 inches in diameter at the top 
and cut out approximately the following grades of lumber: 
Per cent. 
HE OED OUT Shes ts Mine Ba ea pe pg os ee a Se iti 
SESE Sts Spmreart a lie SECO TN Ses a a os SS Se ie pis aoc: 0) 
INOS | =COMMON= 22 — 2.25 =e ST Sie Re Be ae Be erie Da ea ea 35D 
INOse2 2 COMMON 22-27 ee a ts NS a Ee ew Sh 15 
INDI. COMMO HE tbl 8 po Sete acer ii ri ire ae rrye ry! Seely 2 3 
This lumber was graded, moreover, in 1901, when grading rules 
were more rigid than at present. Under present grading rules a 
large proportion of this material would be put in the next higher 
grade. In the judgment of some millmen, timber of this quality 
would run now more nearly as follows: 
Per cent. 
TS OCD OATS oes i ee yd se Sia Seen NOR, as. Smear 15 
PITStSe ale ~SCCONGMS =. See ise ae 3 
IN Gala C OTMIN OM eo ee a Beton wees se 
INO COMNNON: = ee se let rfl a ree 5g Ne 10 
Nos paCOMiMION Pw IEE bis) seal OL Ges BID: Jaa? 
Unfortunately, no records of similar tallies for stands as young 
as 85 years were found. Several millmen of wide experience, how- 
ever, gave estimates differing but very little on the probable propor- 
tion -of grades that could be cut from logs ranging from 14 to 24 
