254 PROCEEDINGS OF SECTION D. 
scorched the hulls of their vessels so as to form a crust of char- 
coal an inch thick. Much risk was incurred of destroying the 
vessels in the process. 
A remedy once proposed was to cover the face of submerged 
woodwork with fascines of brushwood. Some measure of success 
may be achieved hy this method where the brushwood becomes 
clogged with sediment, and thus prevent the shipworm, not from 
reaching the timber, but from obtaining on arrival access to pure 
water. 
The Dutch experimented unsuccessfully in studding the wood 
with broad-headed nails, driven in close together. It was claimed 
that the heads, in rusting, practically united in one sheet of 
armour. 
Tarring, painting, and sheathing with metal are variations of 
one idea. Each and all are good only as long as perfect; a 
mere film, however thin, of each will suffice to exclude the infant 
shipworm, but an abrasion, so small as to be invisible to the eye, 
will admit the pest. Woodwork such as it is desired to protect 
is, unfortunately, peculiarly liable to.abrasion. Vessels touch- 
ing at a wharf grate against the piles; the rise and fall of the 
tide or the shock of the waves equally grind any floating object 
against them. Vessels touch on the bottom and injure the coat- 
ing of their hulls. In a warm climate, such as ours, metals de- 
teriorate in the sea by chemical action more rapidly than in 
colder latitudes. 
In using tar it is recommended to char the wood thoroughly, 
apply the tar hot, and follow with a coat of sand. This is 
more economical and, perhaps, more efficacious than copper 
sheathing. 
A cheap and fairly successful means of providing piles with an 
invulnerable coat is an American method of wrapping around 
them a composition of asphalt and netting, or a mat of canvas 
and bitumen. 
An admirable cure for infected piles, at once inexpensive and 
thorough, is thus described by Snow :—“ Cylinders of earthen- 
ware pipes joined together by a special cement are lowered over 
the pile and pushed into the bottom. The space between the 
cylinder and the pile is then filled with sand. Any fracture or 
leakage is made evident at the top, and can at once be made 
good (/). The sand, of course, operatés by choking the ship- 
worms.” 
SUMMARY. 
Some of the principal points in the foregoing essay may be 
here conveniently condensed. The species of shipworms infest- 
ing Australasian waters, miscalled Z’eredo, are shown to be 
numerous and to be totally distinct from those of Europe or 
America. Observations and deductions made'by foreign writers 
(Kk) Snow. Op. cit., p. 427. 
