A. The condensed vapour of the air frozen, and precipitated to the earth.

A. When the air is nearly saturated with vapour, and condensed by a current of air below freezing point, some of the vapour is squeezed out, and frozen into snow.

A few years ago, some fishermen (who wintered at Nova-Zembla), after they had been shut up in a hut for several days, opened the window, and the cold external air rushing in, instantly condensed the air of the hut, and the vapour (which was squeezed out) fell on the floor in a shower of snow.

A. Because the sun’s rays are too oblique to heat the surface of the earth; and (as the earth has no heat to radiate into the air) the air is very cold.

A. When flakes of snow (in their descent) pass through a bed of air above freezing point, they melt; and fall to the earth as half-melted snow or sleet.

A. To keep the earth warm, and to nourish it.

A. Because it is a very bad conductor; in consequence of which, the earth which is covered with snow, very rarely descends below freezing point, even when the air is 15 or 20 degrees colder.

A. Because air is confined and entangled between the crystals, and air is a very bad conductor; when, therefore, the earth is covered with snow, it cannot throw off its heat by radiation.

A. The Psalmist says—“The Lord giveth snow like wool:” and he means not only that snow is as white as wool, but that it is also as warm as wool.

A. Because air is entangled between the fibres of the wool, and air is a bad conductor.

A. Because air is entangled between the crystals of the snow, and air is a bad conductor.

A. Because it supplies it with moisture for a considerable time; which penetrates slowly into the soil, and insinuates itself through every clod, ridge, and furrow.

A. No snow reaches the general surface of the earth in summer time, because the heat of the earth melts it in its descent.

A. 1st—Because the air is more rarefied; and rarefied air abstracts heat which it holds in a latent state:

2ndly—As the mountain top is not surrounded by earth to radiate heat into the air; therefore, the snow is not melted in its descent, but falls on the mountain, and lies there.

A. Snow is formed of an infinite number of very minute crystals and prisms, which reflect all the colours of the rays of light; and these colours uniting before they meet the eye, cause snow to appear white.

A. Rain, which has passed in its descent through some cold bed of air, and has been frozen into drops of ice.

A. This is frequently caused by electricity in the air, unequally distributed.

A. 1st—Because the congelation of water into hail disturbs the electricity of the air: and

2ndly—The friction (produced by the fall of hail) excites it still more.

A. 1st—Because the air is more highly electrified in summer and autumn: and

2ndly—The vapours (being rarefied) ascend to the more elevated regions, where the cold is greater than it is nearer the earth.

A. Two strata of clouds having opposite electricities, and two currents of wind. The lower cloud (being negative) is the one precipitated.

A. The vapour of the clouds or air condensed, and precipitated to the earth.

A. When the air is saturated with vapour, if a cold current condenses it, it is no longer able to hold all its vapour in solution, and some of it is squeezed out, and falls as rain.

A. The vapoury particles in their descent attract each other; and those which are sufficiently near, unite and form into a drop.

A. When the air is not near saturation (although condensed by the chill of evening), it will still be able to hold its vapour in solution.

A. Because the cloud (travelling about on the wind) comes into contact with something that chills it; and its vapour being squeezed out, falls to the earth as rain.

A. When the rain-cloud is floating near the earth, the drops are large, because such a cloud is much more dense than one which is more elevated.

The size of the rain-drop is increased according to the rapidity with which the vapours are condensed.

A. Yes; by blowing two or more drops into one.

A. 1st—Because the clouds are heavy with abundant vapour: and

2ndly—As the density of the air is diminished, it is less able to buoy the clouds up.

A. Because the mercury of a barometer falls.

A. Because it contains a compound of hydrogen and nitrogen (called ammonia), which is a very excellent food for young plants.

A. Because rain hastens the putrefaction of the fallen leaves by causing fermentation.

A. 1st—Because it beats down the noxious exhalations collected in the air, and dissolves them:

2ndly—It mixes the air of the upper regions with that of the lower regions: and

3rdly—It washes the earth, and sets in motion the stagnant sewers and ditches.

A. The air (striking against the side of the mountains) is carried up the inclined plane, and brought in contact with the cold air of the higher regions, by which it is condensed, and its vapour squeezed out.

A. Because the water penetrates the pores of the sponge, and drives the particles of the sponge further from each other; in consequence of which, the bulk of the sponge is greatly increased.

A. Because the moisture of the air (penetrating the string) causes it to swell; and (as the cord thickens) its tension is increased, and the string snaps.

A. Because the moisture (penetrating the paper) drives its particles further apart; and (as the moisture is absorbed unequally by the paper) some parts are more enlarged than others; in consequence of which, the paper blisters or puckers.

A. The cowl of the capu’chin is fastened to a piece of cat-gut. When the weather is wet, the moisture swells the cat-gut and it is shortened, by which means the cowl is pulled up; but in dry weather, the string is loosened, and the cowl falls down.

A. The two figures are attached to a piece of cat-gut in such a manner, that when the cat-gut is shortened by moisture, it pulls the man out; but when it is loose, the woman falls out by her own weight.

A. The moisture (by penetrating the threads of the stockings) causes them to shrink in size.

A. Keswick (in Cumberland); and then Kendal (a market town in Westmoreland).

(In Keswick, about 63 inches of rain fall in a year. In Kendal, 58; Manchester, 38; Liverpool, 34; Dublin and Cambridge, 25; Lincoln, 24; London, 21; and in Paris, only 18.)

A. More rain falls by night than by day; because the cold night condenses the air, and diminishes its capacity for holding vapour in solution.

A. There are more rainy days from September to March; but heavier rains between March and September.

A. Because the temperature of the air is constantly decreasing, and its capacity for vapour decreases also; in consequence of which, it is perpetually obliged to part with some of its vapour in rain.

A. Near the equator; and the quantity of rain decreases as we approach the poles.

A. Because the contrast between the night and day is very great. The hot air absorbs moisture very abundantly during the day; and when the cold night condenses the air, it is unable to retain the moisture imbibed, and some of it falls in rain.

A. Water is composed of two gases, oxygen and hydrogen.

(In 9 lbs. of water, 8 are oxygen, and 1 is hydrogen.)

A. Because its particles are kept separate by latent heat; but when a certain quantity of this latent heat is driven out, water becomes solid, and is called ice.

A. By increasing its latent heat, the particles, of water are again subdivided into invisible steam.

A. Because it is laden with foreign matters, and will not readily dissolve substances immersed in it.

A. Because when it filters through the earth, it becomes impregnated with sulphate of lime, and many other impurities from the earths and minerals with which it comes in contact.

A. Because the soda of the soap combines with the sulphuric acid of the hard water, and the oil of the soap with the lime, and float in flakes on the top of the water.

N.B. Sulphate of lime consists of sulphuric acid and lime.

A. Because salt water contains muriatic acid; and the soda of soap combines with the muriatic acid of the salt water, and produces a cloudiness.

A. The muriatic acid of the sea-water disturbs the gallic acid of the black dye, and turns it red.

A. Of kelp (or the ashes of sea-weed dried and burnt in a pit) mixed with oil or fat.

Yellow Soap is made of whale-oil, soda, and resin. Soft soap is made of oil and potash. Hard soap of oil and soda.

A. Because the oxygen of the water attaches itself to the stains of the linen, and dissolves them; as oxalic acid dissolves ink spots.

A. 1st—Because soap increases the oxygen of the water: and

2ndly—It neutralizes the grease of the things washed.

A. Because it has not come in contact with earths and minerals.

A. Because it unites freely with the soap, dissolving it instead of decomposing it, as hard water does.

A. 1st—Because the carbonic acid of the wood ashes combines with the sulphate of lime in the hard water, and converts it into chalk: and

2ndly—The sulphuric acid of the water combines with the potash of the wood ashes, and prevents it from neutralizing the oily matter of the soap.

A. Because it is impregnated with decomposed organic matter, washed from roofs, trees, or the casks in which it is collected.

A. Because very minute particles of water insinuate themselves into the pores of the sugar, and force the crystals apart from each other.

A. Because very minute particles of water insinuate themselves into the pores of the salt, and force the crystals apart from each other.

A. Because the sugar or salt (being disunited into very minute pieces) floats about the water, and mixes with every part.

A. 1st—Because the heat of the water entering the pores of the sugar or salt, opens a passage for the water: and

2ndly—The particles of hot water being smaller than those of cold, can more readily penetrate the pores of salt or sugar.

A. 1st—Because it contains mines of salt at the bottom of its bed:

2ndly—It is impregnated with bituminous matter, which is brackish: and

3rdly—It contains many putrid substances, which increase its brackishness.

A. Because salt will not evaporate; and, therefore, when sea-water is turned to vapour, its salt is left behind.

A. Because leaves, plants, insects, &c. are decomposed in it.

A. Because numberless insects lay their eggs in the leaves and plants which float on the surface; these eggs are soon hatched, and produce swarms of worms, eels, and insects.

A. 1st—Because the motion of running water prevents its fermentation:

2ndly—It dissolves the putrid substances which happen to fall into it: and

3rdly—It casts on the bank (by its current) such substances as it cannot dissolve.

A. 1st—Because it impinges against its banks, and is perpetually diverted from its forward motion: and

2ndly—Because the centre of a river flows faster than its sides.

A. Because they rub against the banks, and are delayed in their current thereby.

A. Because the soap makes the water tenacious, and prevents the bubbles from bursting as soon as they are formed.

A. Because it is not tenacious enough to hold together the bubbles that are formed.

A. Because they are filled with warm breath, which is lighter than air.

A. Frozen Water. When the air is reduced to 32 degrees of heat, water will no longer remain in a fluid state.

A. Because water expands by freezing; and as the bulk is increased, the gravity must be less.

Nine cubic inches of water become ten when frozen.

A. Because the water in them freezes; and as the water is expanded by frost, it bursts the ewers to make room for its increased volume.

A. Because the surface is first frozen, and the frozen surface acts as a plug, which is more difficult to burst than the earthen ewer itself.

A. Because the moisture (which they imbibed) freezes, and by its expansion splits the solid mass.

A. The water in these hollows froze first at the sides of the foot-prints: other crystals gradually shot across the water, and would have covered the whole surface, had not the earth absorbed the water before it had time to freeze.

A. The air being colder and the earth harder (than in the former case), the entire surface of the foot-print is frozen over, before the earth can draw the water in.

A. Because the earth absorbs the water, and leaves the icy film behind.

A. Yes; it expands as soon as it is more than 42 degrees till it boils, and then it flies off in steam.

A. Because the water in them freezes; and as the water expands by frost, it bursts the pipes to make room for its increased volume.

A. Water (which is wisely ordained by God to be an exception to a very general rule) contracts till it is reduced to 42 degrees, and then it expands till it freezes.

(Water freezes at 32°.)

A. Because it is converted into solid crystals, which do not fit close, like the particles of water.

A. Because when water is colder than 42 degrees, it instantly ascends to the surface; and (if it freezes) floats there till it is melted.

(When a river is frozen, the water below the surface is never less than 42°.)

A. If ice were heavier than water, it would sink; and a river would soon become a solid block of ice, which could never be dissolved.

A. 1st—Water is a very bad conductor, and is heated or chilled by convection only:

2ndly—If the ice on the surface were to communicate its coldness to the water beneath, the water beneath must communicate its heat to the ice, and the ice would instantly melt: and

3rdly—The ice on the surface acts as a shield to prevent the cold air from penetrating the river to freeze it below the mere crust.

A. Because the surface is in contact with the air, and the air carries away its heat.

A. Because the heat of the water (immediately below the frozen surface) passes through the pores of the ice into the cold air.

A. Because water is so slow a conductor, that our frosts never continue long enough to convert a whole river into a solid mass of ice.

A. 1st—Because the motion of the current dissolves the crystals as fast as they are formed; and

2ndly—The heat of the under surface is more freely distributed to the upper surface by the rolling water.

A. Because little flakes of ice are first formed and carried down the stream, till they meet some obstacle to stop them; other flakes of ice (impinging against them) are arrested in like manner; and the edges of the different flakes overlapping each other, make the surface rough.

A. Because springs issue from the bottom, and (as they bubble upwards) thaw the ice, or make it thin.

A. Because the frosty air is at least 10 or 12 degrees colder than the water.

(The water below the surface is at least 42°; but the air 32°, or even less.)

A. Because (as the whole volume of water must be cooled to 42 degrees before the surface can be frozen) it will take a longer time to cool down a deep bed of water than a shallow one.

A. 1st—Because the mass of water is so great that it requires a very long time to cool the whole volume down to 42 degrees:

2ndly—The ebb and flow of the sea interfere with the cooling influence of the air: and

3rdly—Salt never freezes till the surface is cooled down at least 25 degrees below the freezing point.

A. 1st—Because they are very deep:

2ndly—Because their water is supplied by springs, which bubble from the bottom.

A. As the whole volume of water must be reduced to 42 degrees before the surface will freeze, the deeper the water, the longer it will be before the whole volume is thus reduced.

A. Because they keep continually sending forth fresh water, which prevents the lake from being reduced to the necessary degree of coldness.

A. When frozen water is thawed, it absorbs heat from the air and objects around to melt its ice, in consequence of which the cold is greatly increased.

A. When water freezes it gives out its latent heat, in order that it may be converted into solid ice; and as much heat is liberated from the water into the air, we feel warmer.

A. Water freezes at 32°, but salt and water will not freeze till the air is 25° colder: if, therefore, salt be added to frozen water it becomes liquid, unless the thermometer stands below 7°, (which it never does in our island).

A. Yes; any acid, such as sulphuric, nitric, &c.

A. When salt is mixed with snow, it dissolves the crystals into a fluid; and whenever a solid is converted to a liquid, heat is absorbed, and the cold made more intense.

A. During the warm weather the earth absorbed abundance of moisture, which the winter freezes: and (as water expands by frost) the expanding water thrusts the particles of earth apart from each other, and leaves a chink or crack behind.

A. These cracks in the earth let in the air, the dew and rain, and many gases favourable to vegetation.

A. In spring the ice of the clods dissolves, and the particles of earth (which had been held apart by the expanded ice) are left unsupported, and tumble into minute parts (because their cement is dissolved).