TEREDO.
“This,” said Mr. Miller, “is a piece of wood, which was once, perhaps, part of a ship that has been wrecked; at all events, it has been a long time in the water. The holes were made by a kind of worm, called Teredo, which eats its way into the hardest timber, making it so weak that a slight blow will crush it. In some seas the Teredo is so abundant, that no vessel is safe unless its bottom is entirely coated with copper. The worm is very small when first it gets into the wood, but grows larger as it eats its way, making a passage through the whole length of a plank, but never coming to the surface; so that a beam of timber may appear to be solid, and yet all the while be within as full of holes as a sponge. As it goes on, it lines its passage with a white shell, which it has the power of making.” In one of the holes a portion of the white shell was still remaining.
“Is it not,” continued Mr. Miller, “a wonderful little animal? It can work its way in the dark, through solid wood, taking care never to turn a quarter of an inch too much towards the right or towards the left. It is taught by God to line its house with shell, but no one knows how it works, or what materials it employs; and, worm as it is, the boldest sailor would refuse to go to sea in a ship which it had taken hold of. It may lead us, too, to despise nothing that God has made, however trifling it may appear.”
BARNACLES.
The next thing picked up was a piece of cork, covered with barnacles. Barnacles are small shell-fish, growing on long leathery stems, by which they fasten themselves to floating wood, or the bottoms of vessels. They are not so mischievous as the worms mentioned before, as they do not actually eat the wood; but when, as is sometimes the case, they thickly cover the bottom of a ship, they prevent it from going quickly through the water. It is sometimes found necessary to take a ship into a dock, in order to scrape off the barnacles.
A piece of stone picked up by Henry, looking like a coal-cinder, but white, Mr. Miller said was pumice-stone. It is one of the kinds of stone thrown up by volcanoes, or burning mountains. It is so light that it floats on water. He thought that this piece might, perhaps, have been thrown from a burning mountain into the sea, or that it might have been thrown overboard from a ship. It is used on board ships to scrub the decks with, and on land painters use it in scraping off paint from wood which is to be coated afresh.
“On the whole,” said he, “most probably it came direct from a volcano, for I scarcely ever came to this part of the coast without finding some, and it could scarcely happen that pumice-stone would always be falling overboard by accident.”
WHELK.