t 
- 186 BOTANICAL INFORMATION. 
valued friends, Captain Sir William Symonds, the late Surveyor-General 
of the Navy, and from John Edge, Esq., F.R.S., the present Deputy- 
Surveyor of the Navy, which cannot fail to be interesting to our 
readers, and with which we shall close our remarks for the present, 
feeling sure that what we have here given will be the means of eliciting 
much more valuable information on this important subject. 
It was about the year 1819 that the value of African Oak or Teak was 
first experienced in the British Navy, and it has proved of the highest 
importance for certain parts of a vessel The Nimrod, a 28-gun 
ship, is built of it; but the weight of the wood is much against it asa 
material exclusively, and, of late, its use has been confined to beams, keel- 
sons, waterways, shelf-pieces, and framing of bitts, &c. ; so that, in the 
opinion of many, for such purposes no timber is comparable to it, except 
the ** Sabicu " (Acacia formosa, H.B.K.), from Cuba. The juice or sap 
of the wood is bitter, not, like that of oak, acid; on which account 
its contact with other timber is less pernicious, the sap of oak being 
very destructive in that way. It is, however, heavier than either 
English Oak or Indian (Malabar) Teak. The average of many experi- 
ments gives for English Oak and Malabar Teak, when seasoned, about 
49 lbs. to the cubic foot; while the specific gravity of African Oak 
is more than 60 lbs. (often 70 lbs.) to the cubic foot. The 4/rican 
Oak, again, is by far the strongest of these woods, and requires nearly 
- one-third more weight to break it than either English Oak or Malabar 
Teak; while Sabicu is nearly of the same strength. “ Greenheart " 
(Nectandra Rodisei, Sehom. in Hook. Lond. Journal of Botany, vol. iii. 
p. 626) is indeed one-third stronger than African Oak, but its 
qualities are little known as yet from experience. African Oak rots 
in warm, damp, and confined situations ; while Indian Teak and Sabieu 
are durable under such circumstances, and, indeed, almost imperishable. 
Tab. VI. Leaf of Oldfieldia Africana. Fig. 1. Seedling plant, about 
a week old; fig. 2. fruit ; fig. 3, ditto with one valve removed, showing 
_ two of the seeds, corresponding with the two cells in the valve ; fig. 4, 5, 
seed :—all nat. size ; fig. 6, section of a seed; fig. 7, transverse section 
` of the albumen and cotyledons; fig. 8, embryo, slightly magnified. 
