XXVII.] 
CANADA ELM. 
227 
wood for the converter to deal with, the instances of 
defects being found in opening it, arising either from 
pruning or from accidental causes, being extremely 
rare. 
About 2,500 to 3,000 loads of this wood are imported 
annually into each of the London and Liverpool markets, 
to meet the wants of private dealers, who employ it for 
coach-making, turnery, boat-building, &c. The Govern¬ 
ment also take about 600 to 700 loads annually for the 
use of the royal dockyards, stipulating in their contracts 
that it shall be of the first quality, from 11 to 15 inches 
square, averaging 12^ inches; 20 feet and upwards in 
length, averaging at least 24 feet in length, and to be 
well squared, and free from knots. 
The Canada Rock Elm is a remarkably slow-growing 
tree, the slowest in fact with which we have to deal; it 
makes only one inch of wood diameter in about fourteen 
years.* 
Table CXVII.— Rock Elm (Canada). 
Transverse Experiments. 
Number 
of the 
1 specimen. 
Deflections. 
Total 
weight 
required 
to break 
each 
piece. 
Specific 
gravity. 
Weight 
reduced 
to 
specific 
gravity 
700. 
Weight 
required 
to break 
1 square 
inch. 
With the 
apparatus 
weighing 
390 lbs. 
After the 
weight 
was 
removed. 
At. . 
the crisis 
of 
breaking. 
Inches. 
Inch. 
Inches. 
lbs. 
lbs. 
I 
I - 6o 
•25 
875 
935 
760 
86l 
23375 
2 
1-85 
•30 
875 
946 
753 
893 
236-50 
3 
i 75 
•30 
9-00 
899 
735 
85b 
224 75 
4 
1 '90 
‘35 
8-65 
918 
740 
868 
229-^0 
5 
1-85 
•25 
875 
927 
738 
879 
23175 
6 
1 ’55 
•30 
9 ‘05 
895 
765 
819 
22375 
Total . 
10-50 
175 
5275 
5 ) 52 o 
4491 
5176 
1380-00 
Average 
i 75 
•29 
879 
920 
1 00 
863 
230-00 
Remarks. —All fractured and crippled, but not completely broken asunder. 
* See Tabular Statement in Chapter II., on the comparative rate of 
growth of trees, p. 18. 
