The Teredo Navalis on Colonial Timber. fer ft) 
members some few facts which have lately been observed 
with relation to the action of the worm upon some piles 
forming a portion of the Wharf. These Gum or Stringy 
Bark piles formed a part of the intended Franklin 
Wharf: they were driven in front of the proposed entrance 
into the new basin,* and have been necessarily removed in 
order to clear the entrance. From information, which I 
believe may be depended upon, it appears that they have 
been driven about eight years: they have been exposed dur- 
ing that time to probably a heavier wash of the sea than any 
of the piles on the New Wharf; but in other respects they 
are similarly situated to these. 
The timber at the head and foot appears perfectly sound : 
that portion which was buried, by being driven into the 
sand composing the bottom of the harbour at the point from 
whence they have been removed, shows no evidence of the 
action of the worm, or of any other kind of decay; and the 
head above the line of high-watermark appears equally 
sound. Between these two points, that is, high-watermark 
and the surface of the ground, the piles appear to have been 
acted upon by the worm pretty equally ;—the timber is not 
affected more between high and low watermark than at the 
bottom. Judging from the external appearance of the piles, it 
would seem that there have been at least two kinds of worm at 
work; the T’eredo navalis has burrowed in places into the 
very heart of the timber: but the principal agent in the 
destruction would appear to be a smaller insect, whose action 
is altogether on the surface. 
The piles which were examined averaged about one foot 
in diameter; they had been driven 10 or 12 feet into the 
ground, and the part acted upon by the worm was about 15 
feet in length. In two instances the piles were girthed at: 
* Constitution Dock. 
