II.

Magnet is found in the earth with iron ore. Where there is magnet in the ore, the iron is of the best quality. The magnet resembles iron.

If you put a piece of iron on a magnet, the iron itself begins to attract other iron. And if you put a steel needle on a magnet, and hold it thus for awhile, the needle will become a magnet, and will attract iron. If two magnets are brought together at their ends, one side will turn away from the other, while the other sides will be attracted.

If a magnetic rod is broken in two, each half will attract at one end, and will turn away at the other end. Cut it again, and the same will happen; cut it again, as often as you please, and still the same will happen: equal ends will turn away from each other, while opposite ends will be attracted, as though the magnet were pushing away at one end, and pulling in at the other. No matter how you may break it, it will be as though there were a bump at one end, and a saucer at the other. Whichever way you put them together, a bump and a saucer will meet, but a bump and a bump, or a saucer and a saucer will not.

III.

If you magnetize a needle (holding it for awhile over a magnet), and attach it in the middle to a pivot in such a way that it can move freely around, and let it loose, it will turn with one end toward midday (south), and with the other toward midnight (north).

When the magnet was not known, people did not sail far out to sea. When they went out far into the sea, so that land was not to be seen, they could tell only by the stars and the sun where they had to sail. But when it was dark, and the sun or stars could not be seen, they did

not know which way to sail. And a ship was borne by the winds and carried on rocks and wrecked.

So long as the magnet was not known, they did not sail far from the shore; but when the magnet was discovered, they made a magnetic needle on a pivot, so that it should move around freely. By this needle they could tell in which direction to sail. With the magnetic needle they began to sail farther away from the shores, and since then they have discovered many new seas.

On ships there is always a magnetic needle (compass), and there is a measuring-rope with knots at the stern of a ship. This rope is fixed in such a way that when it unrolls, they can tell how far the ship has travelled. And thus, in sailing in a boat, they always know in what spot it is, whether far from the shore, and in what direction it is sailing.

MOISTURE

I.

WHY does a spider sometimes make a close cobweb, and sit in the very middle of its nest, and at other times leave its nest and start a new spider-web?

The spider makes its cobweb according to the weather, both the present and the future weather. Looking at a spider, you can tell what kind of weather it is going to be if it sits tightly in the middle of the cobweb and does not come out, it means that it is going to rain. If it leaves the nest and makes new cobwebs, it is going to clear off.

How can the spider know in advance what weather it is going to be?

The spider's senses are so fine that as soon as the moisture begins to gather in the air, though we do not yet feel it, and for us the weather is clear, for the spider it is already raining.

Just as a naked man will feel the moisture, when a man in his clothes does not, so it is already raining for a spider, while for us it is only getting ready to rain.

II.

Why do the doors swell in the winter and close badly, while in the summer they shrink and close well?

Because in the fall and winter the wood is saturated with water, like a sponge, and spreads out, while in the

summer the water comes out as a vapour, and the wood shrinks.

Why does soft wood, like aspen, swell more, and oak less ?

Because in the hard wood, in the oak, the empty places are smaller, and the water cannot gather there, while in the soft wood in the aspen, there are larger empty places, and the water can gather there. In rotten wood these empty places are still larger, and so rotten wood swells most and shrinks most.

Beehives are made out of the softest and rottenest wood; the very best are made from rotten willow wood. Why? Because the air passes through the rotten wood, and in such a hive the bees feel better.

Why do boards warp?

Because they dry unevenly. If you place a damp board with one side toward the stove, the water will leave it, and the board will contract on that side and will pull the other side along; but the damp side cannot contract, because it is full of water, and so the whole board will be bent.

To keep the floors from warping, the dry boards are cut into small pieces, and these pieces are boiled in water. When all the water is boiled out of them, they are glued together, and then they never warp (parquetry).

THE DIFFERENT CONNECTION OF PARTICLES

WHY are cart bolsters cut and wheel naves turned not from oak, but from birch? Bolsters and naves have to be strong, and oak is not more expensive than birch.

Because oak splits lengthwise, and birch does not split, but ravels out.

Because, though oak is more firmly connected than birch, it is connected in such a way that it splits lengthwise, while birch does not.

Why are wheels and runners bent from oak and elm, and not from birch and linden?

Because, when oak and elm are steamed in a bath, they bend and do not break, while birch and linden ravel in every direction.

This is again for the same reason, that is, that the particles of the wood in the oak and in the birch are differently connected.