UTILIZATION OF CALIFORNIA EUCALYPTS. 19 
TABLE 4.—Strength of some of the eucalypts of Australasia. 
[Taken from the ‘‘Supplement to the Western Australian Timber Tests,” 1906, by G. A.Julius, B. Sc. M. E.] 
[Green material. Average values.] 
= Compres- 
Weight 3 
per cu- Bending. SA F 2 
bic foot. allel to 
grain. 
| 
+ 22) F 32 (22 Ip la © 
ier 5 | 2i\e| |#eai8s a mS 
Localname. Botanicalnmame. | Where grown. ls |3| 4 [2 2sle5 Zu |¢ lage 
eg|/5 (S| laes/se als | & 
ole lol|]xHiBssiay. Oj |wU . 
S215) 8 |2SaEsa|8Sa| 3 Aas 
€ |3/2/ 85 |Seseeslsce) g age 
= > Ss SEB alora MUanl| 5 | 
=a te hg Ag = = G |O 
Blue gum EB... globulus.~ = ..<::- WaSiAanin = 22. hee 70; 49} 44) 142) 8, 700/12, 100) 2, 450) 41) 5,500 
aap ee) Bee “(Te Pens ad ae ER se Wietonin. 2/6227. 69 49] 40] 139] 9,000/12, 000] 2,250] 37) 5,850 
Hed om} B. restirateas: «2225.2 1.: ee 6 a ee ae 64, 44) 44) 112) 5,100) 6,800 740| 43) 3,750 
Ironbark ...| E. ae and | New South Wales...| 80, 57! 40) 160/12, 450)14,600) 2,175) 35) 7,750 
crebra. 
Jarrah: -2<- [DAR ithigs ti iF. pm Western Australia..} 68) 48) 50) 203) 8,300/10, 600} 1,450! 290) 6,250 
Rar 3. B. diversicoler:= ==. -=}.- =. Ome ae eee 72} 50) 54) 312) 8,600/11, 500) 1,750) 385) 5,500 
Paar = 5 E. gomphocephala. .|....- GOe 2. eee 78| 60} 43) 318} 9,300/11, 800} 1,630) 331) 6,975 
Wandooe--=-) b-redunea--...-. 5-1... -2 GOs) 2k es soe 7$| €2] 28] 287/11, 750/14, 000) 1,850) 324) 8,320 
Natess=-—-- HS eonmnia-t oe 2 ee dent esses se 79| 64] 32) 122/12, 700)16, 700) 2,300 ig 6, 660 
SHRINKAGE. 
In order to determine the amount of shrinkage in blue gum, 28 
pieces, 24 by 24 by 12 inches, were dried out slowly from a green to 
a bone-dry condition. Sixteen of the pieces were selected so that 
two sides were tangential to the annual rings of growth, while in the 
other twelve the rings ran diagonally. The drying was carried on 
first in a warm room and finally in an oven. The pieces were weighed 
and measured at intervals for a period of about one year. 
When a piece of green or wet wood is dried, no change in dimen- 
sions takes place until a point called the “‘fiber-saturation point”’ 7 
(generally in the neighborhood of 30 per cent moisture) is passed. 
The wood then begins to shrink in cross-sectional area and con- 
tinues to do so uniformly with the removal of moisture until it is 
bone dry. Longitudinal shrinkage is so small as to be negligible. 
As a rule the heaviest wood shrinks the most, and sapwood shrinks 
more than heartwood of the same specific gravity. Shrinkage is 
oreater also in the direction of the circumference of a log than in a 
radial direction. 
The shrinkage tests on blue gum showed an average shrinkage in 
volume of 21.8 per cent ® when pieces were dried from a green to an 
oven-dry condition. Of this amount about 7 per cent is radial 
@ For a full discussion of the fiber-saturation point, see Forest Service Circular 108, 
“The Strength of Wood as Influenced by Moisture,’? by H. D. Tiemann. 
6 All shrinkage percentages are given on a basis of oven-dry volume. 
[Cir. 179] 
