260 MAGAZINE OF SCIENCE AND ART. 
If the beam be uniformly loaded through¬ 
out the formula is—• 
l 3 10 
E—5_ 
XJ -g 
1G ad 3 S 
It is unnecessary to extend the expla¬ 
nation of the use of these values by work¬ 
ing out examples. Any one desirous of 
further information on the subject may 
obtain it by consulting “ Barlow on 'Mate¬ 
rials and on Construction,” from which 
I these rules have been taken. 
Results of Experiments on the Elasticity and Strength of Timber in New South Wales, procured 
through the Chief Commissioner for Railways, and tested at the Sydney Branch of the Royal 
Mint, in the month of Maxell, 1858. 
d 
O 
a 
a 
M 
W 
tM 
o 
o 
& 
Names 
of the woods 
and 
Dimensions. 
Specific Gravity. 
Greatest Weight 
and Deflection 
while the Elasticity 
remained Perfect. 
*3 
£ » 
-2d 
’"d 
a» 
p5 
Ultimate Deflection 
in inches. 
Value of E. 
from 
the formula 
l 3 iv 
Value of S. 
from 
the formula 
l w 
Weight 
in lbs. 
Deflec¬ 
tion in 
inches. 
16 a d3 S 
4 a d2 
1 
Iron Bark. 
952 
1.85 
952 
1.85 
1205 
2 
4 feet between 
784 
1.40 
1120 
2.90 
3 
Supports and 
616 
1.05 
952 
2.10 
1218 
4 
1J inch square 
61G 
.95 
1064 
2.35 
Mean results 
1211 
742 
1.31 
1022 
2.30 
417400 
2288 
1 
Steingv Baek. 
f 
560 
1.20 
784 
2.85 
o 
4'ft. betwn. supts. 
voo 
560 
1.30 
784 
2.60 
3 
and 1J in. square 
Q3<) 
560 
1.15 
840 
2,25 
- 
4 
560 
1.15 
840 
2 30 
Mean results 
937 
560 
1.20 
812 
2.50 
343900 
1818 
1 
Box. 
r 
672 
0 90 
1008 
1.80 
1232 
o 
4 feet between 
672 
.90 
1064 
1.85 
3 
bearings and 
672 
.90 
1176 
2.50 
1228 
4 
1 | inch square 
616 
.90 
1120 
1.85 
Mean results 
1230 
658 
.90 
1092 
2.0 
538.800 
2445 
1 
Spotted Gum. 
560 
.95 
810 
1.9 
981 
2 
4 feet between 
560 
.90 
896 
1.8 
3 
bearings and 
560 
.90 
896 
2.05 
1051 
4 
If inch square 
l 560 
.75 
952 
2.10 
Mean results 
1035 
560 
.85 ■ 
896 
1.96 
485.500 
2006 
* Note .:—For the sake of simplifying the calculations, the value of E. is not carried on exact beyond 
the nearest fourth figure. 
