The gunboats constructed during the Crimean war suffered far more from dry rot and the teredo than the shot and shell of the Russians. One cannot even guess at the mischief perpetrated every year all along our shores, in docks and harbours, by the boring animals that penetrate all woods not specially protected. We cannot count the number of the ships that have foundered at sea, owing to those few inches of timber, on which all depended, being pierced or destroyed by the worm or fungus.
In the short space of twelve years these destructive worms were known to make such havoc in the fir piles of a bridge at Teignmouth, that the whole bridge fell suddenly, and had to be totally reconstructed.
The wooden piers of Bridlington were nearly wholly destroyed by worms; and the pile fenders on the stone piers at Scarborough were generally cut through in a few years.
At Dunkirk, wooden jetties are so speedily eaten away that they require renewal every twelve or fifteen years. At Havre, a stockade was entirely destroyed in six months. At Lorient, wood only lasts about three years in the sea-water; and at Aix, the hull of a stranded vessel was found to have lost half its weight in six months, from the ravages of these animals.
The reason why Balaclava, in Russia, is not a place of considerable mercantile importance is owing in a great measure to the destructive ravages of the worms with which its waters are infested, and by which the hulls of ships remaining there for any length of time become perforated.
The piles of the jetties in Colombo Harbour, Ceylon, which are mostly of satin-wood, and about 14 inches in diameter, are so pierced by these worms in the course of twelve months as to require renewal.
Portion of pile, from Balaclava harbour, Russia; riddled by the Teredo Navalis.
The cofferdam at Sheerness was destroyed by the teredo. After a time, it was no uncommon occurrence to see several piles, apparently sound, floated away at each tide; indeed, they were so thoroughly perforated by the teredo that in still weather, by putting the ear to the side of the pile, the worms could be heard at their boring labours.