No. 237 Maritime Archaeology in the People's Republic of China ...

Appendix 2. Wood identification
Three samples of wood, one excavated from a wreck site in
China (Bai Jiao 1) and two obtained from dredge operators,
were examined to determine their wood type. Of the samples
recovered by dredging the thinner of the two samples is solid
and in very good condition whilst the other sample is soft and
appears to be quite degraded. Sample Bai Jiao 1 is encrusted
with concretion and also appears to be quite degraded. A small
piece was removed from each sample and the transverse section
polished to a 1200 grit finish prior to low power microscopic
examination. Where possible, radial and tangential longitudinal
surfaces were sectioned (microtome) and slides prepared for
high power microscopic examination. The results of these
examinations are described below.
Dredge Timbers
tr a n S v e r S e Su r fa C e
Samples A and B possessed identical features resin canals
were present, with the majority in the more dense late wood
bands. The bands of late wood had approximately the same
dimensions as those of the early wood and there was a very
clear demarcation between the late and the early wood. The
greater degree of degradation of Sample B was demonstrated
by the substantial collapse and distortion (sideways collapse)
of the early wood sections. Thin epithelial cells surround the
resin canals.
ra d i a l lo n G i t u d i n a l Su r fa C e
Despite its apparently good condition a suitable slide could
not be made of Sample A. A slide of Sample B showed the
presence of smooth-walled ray tracheids and large windowlike
simple pits in the ray parenchyma. A polished section of
Sample B confirmed the presence of similar pits in the ray
parenchyma of this sample but the nature of the walls of the
ray tracheids could not be determined owing to the lack of
definition produced by polishing.
The size of the resin canals and the thin nature of the
epithelial cells indicate that the sample is a pine rather than
a larch, spruce or Douglas fir. The size and demarcation of
the late wood bears most resemblance to that of the pitch
pines. The features observed in the radial section however
are typical of soft pines of the yellow pine type. On the basis
of the microscopic anatomical features this sample is more
likely to be a yellow rather than a pitch pine. Pines of the
yellow pine type include Pinus strobus L. (yellow pine), P.
lambertiana Dougl. (sugar pine), P. monticola Dougl. (western
white pine), P. cembra L.v. sibirica Loud. and P. koraiensis
Sieb. et Zucc. (Siberian yellow pine, Siberian pine, Korean
pine, Manchurian pine). The latter group of pines are native
to Siberia and eastern Asia. Yellow pine is low in strength and
works easily but is not resistant to decay.
Bai Jiao 1
tr a n S v e r S e Su r fa C e
The sample is a highly degraded softwood. Although areas of
degradation on the transverse surface resembled resin canals
none could be positively identified. There is an abrupt transition
between the early wood and the late wood with a much greater
abundance of the early wood. Rays are clearly visible.
ta n G e n t i a l lo n G i t u d i n a l Su r fa C e
Predominantly uniseriate rays observed, ranging in height
from 6 to 25 cells high.
ra d i a l lo n G i t u d i n a l Su r fa C e
Evidence of spiral thickening in the axial tracheids. Cupressoid
cross-field pits were observed in the ray parenchyma.
The features identified above are found in yews (Taxus
sp). Thus although the sample is highly degraded it is likely
to be of this timber type. Yew occurs commonly in western
and central Europe and less commonly in western Asia and
North Africa. It is a strong, durable and resilient wood that is
resistant to splitting.
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