216 
Supplement to the " Tropical Agriculturist." 
[Sept. 1, 1900. 
80, and considering the age of the specimens (which 
we think should be noted) the report is a most 
favourable one for Ceylon timbers. We quote as 
follows from the report : — 
The precise combination of qualities required 
in a timber for special purposes, including facility 
of working, uniformity of structure and freedom 
■from defects, appearance, durability, and other 
qualities, is not to be determined from mechanical 
tests alone. Further, the results of mechan- 
ical tests of the same limber vary with the 
locality in which the timber is grown, the con- 
ditions of felling and seasoning and other circum- 
stances, to a greater extent than is commonly 
supposed. In some 2,000 tests of different logs 
of long les,f pine made for the Government of the 
United States, which had all been selected by the 
forest officers and subjected to the same treatment, 
it was found that the crushing strength varied 
from 2'04 to 4'40 tons per squareiinch ; the co-effi- 
cient of transverse strengtli from 1'90 to 7'2o tons 
per square inch ; and the heaviness from 28 to 65 
lbs. per cubic foot. Hence very definite deduc- 
tions from any set of tests on a limited number of 
logs must be subject to correction. 
For European timbers I take the following 
values as representing fairly what is accepted as 
the averages of such results as are trustworthy : — 
European Timbers. 
a a 
Oak 
Elin 
Ash 
00 M 
CO n3 
2 a 
B s 
> S 
C. 10 c 
u 
.2 - ■§ 
OT O ._ 
c a> q 
0. 
averse 
igth, 
J 8 per 
nch. 
fc 
fb 
u 
(U 
Tran 
strei 
pounc 
S. i 
w. 
w. 
w. 
fb 
52 
10,000 
12,000 
193 
230 
34 
10,300 
8,000 
320 
235 
47 
9,000 
13,000 
191 
277 
37 
8,300 
8,300 
157 
224 
Broadly speaking the strength cf timber in- 
creases with its heaviness. The most valuable 
timbers for structural purposes are those which 
have considerable strength without excessive 
■vceight. The pine timbers so largely used are 
npt only easy to work, but they have good strength 
in proportion to their heaviness. In the above 
table the strengths have been divided by the 
■weights per cub. foot and the results are given in 
the last two columus. Compared in this way, 
Elm is superior to Oak, and even red pine is not 
much inferior. 
Table of Ceylon Timbebs. 
Nam« of Timber. 
Vinakku 
Lanutnidella 
.9- 
i Sa 
MS." 
•2 .S 
p. a; 
41-4 3,490 
40-4 4,290 
20-4 3,200 
a " 
V p a 
fb 
7,820 
Medium 
TiMBEEs. 42 to 60 lb. per c. ft. 
Panakka, 
549 
9,200 
12.960 
167 
Zoo 
47-3 
5,920 
10,8:;0 
125 
ooa 
43-4 
7,550 
6,840 
174 
iOI 
.i 48-1 
6,500 
9,310 
135 
Buriy ani8A'a 
570 
9,300 
14,600 
^63 
Zoo 
489 
6,170 
, 7,790 
126 
ioy 
■Me ndorai 
69-7 
5,810 
13,710 
230 
Ubberiya 
56-7 
7,020 
10,090 
139 
176 
Tawenua 
461 
7,660 
8,070 
iOD 
175 
Margoaa 
47-3 
6,640 
11,480 
140 
244 
Halmilia 
49 9 
7,630 
15,450 
loo 
310 
Suriya 
50-3 
6,-i30 
11,660 
233 
Heavy Timbers, Over 60 lb. c. ft. 
Gurukuja 
62-6 
5,350 
8,740 
86 
140 
S-itiuwood 
64-3 
7,500 
13,780 
116 
214 
Milla 
60-9 
6,630 
14,760 
109 
242 
R mai 
63 3 
5,800 
10,570 
92 
167 
Chomuntiri 
75-5 
6,530 
14,490 
86 
192 
Nedun 
70-8 
8,700 
16,0J0 
125 
226 
Taking the light wood^;, it is clear that as regards 
strength in proportion to vreight, Lunumidella 
and Walukinu stand best. The remarkably light 
wood, Lunumidella, is not absolutely as strong as 
red pine, but in proportion to its weight it is even 
a better timber. VV'ulukiiia is weaker than ash, 
and about the same strength as red pine. 
Of the medium woods, Halmilia is strongest in 
proportion to its weight, and Suriyamara stands 
next. Ubberiya, whicb Mr. Stone thinks well of, 
is somewhat weaker than oak, but it has a greater 
transverse strength than elm. Tawenna has 
nearly the same mechanical properties as Ubberiya. 
Suriyamara is somewhat stronger than either of 
these. 
Tlie heavy timbers do not give very high results. 
Satinwood has greater transverse strength than 
oak, but the strength in proportion to weight is 
not so good. Milla and Chomuntiri have a little 
greater transverse strength, but their crushing 
resistance is low. Nedun is the heaviest, and, for 
cross breaking, the strongest timber. But its 
constants obtained by dividing the strength by the 
weight are not so good as those of European 
timbers. 
I know no tests of the shearing resistance of 
European timbers along the fibre which are trust- 
worthy. But the following results of tests at 
Watertown Arsenal may be used for comparison 
with the tests of Ceylon timbers. 
Shearing Strength. 
Lb. per sq. in. 
Ash — — 458 to 700 
E«d oak — — 726 to 999 
Yellow pine — 286 to 415 
Spruce — — 253 to 374 
Shearing Strength op Cetlon Timbers. 
Shearing Strength 
Name of Timber. 
along fibres. 
Lb. per eq. in. 
w. 
/* 
fc 
fb 
Light Timbers. 
Sapa — 
— 758 
18 
w. 
w. 
"Vinakku — 
— 486 
13 
Lunumidella — 
— 478 
23 
Walukina — 
— 357 
10 
ft. 
Medium Timbers. 
Panakka — 
— 745 
14 
84 
188 
Dawatd — 
— 1,075 
12 
106 
^34 
Jak — 
— 672 
15 
157 
280 
Del — 
— 1,236 
24 
188 
280 
Suriyamara 
- 1,283 
