A Catechism of Familiar Things | Page 3

sun and wind, converted into clouds, which fall in rain, snow, hail, or mist: their falling is occasioned by their own weight in a collision produced by contrary currents of wind, from the clouds passing into a colder part of the air, or by electricity. If the vapors are more copious, and rise a little higher, they form a mist or fog, which is visible to the eye; higher still they produce rain. Hence we may account for the changes of the weather: why a cold summer is always a wet one--a warm, a dry one.
Aqueous, watery; consisting of water.
Collision, a striking together, a clash, a meeting.
Electricity, a natural agent existing in all bodies (see page 18).
What seasons are more liable to rain than others?
The Spring and Autumn are generally the most rainy seasons, the vapors rise more plentifully in Spring; and in the Autumn, as the sun recedes from us and the cold increases, the vapors, which lingered above us during the summer heats, fall more easily.
Recede, to fall back, to retreat.
What is Snow?
Rain congealed by cold in the atmosphere, which causes it to fall to the earth in white flakes. Snow fertilizes the ground by defending the roots of plants from the intenser cold of the air and the piercing winds.
Congealed, turned by the force of cold from a fluid to a solid state; hardened.
Fertilize, to render fruitful.
Intenser, raised to a higher degree, more powerful.
What is Hail?
Drops of rain frozen in their passage through cold air. Hail assumes various figures according to the degrees of heat or cold through which it passes, being sometimes round, flat, &c.
What is the Atmosphere?
The mass of a?riform fluid which encompasses the earth on all sides: it extends about fifty miles above its surface. Air is the elastic fluid of which it is composed.
Elastic, having the power of springing back, or recovering its former figure after the removal of any external pressure which has altered that figure. When the force which compresses the air is removed, it expands and resumes its former state.
What are the uses of air?
It is necessary to the well-being of man, since without it neither he nor any animal or vegetable could exist. If it were not for atmospheric air, we should be unable to converse with each other; we should know nothing of sound or smell; or of the pleasures which arise from the variegated prospects which surround us: it is to the presence of air and carbonic acid that water owes its agreeable taste. Boiling deprives it of the greater part of these, and renders it insipid.
Variegated, diversified, changed; adorned with different colors.
Insipid, tasteless.
What is Wind?
Air in motion with any degree of velocity.
What is Lightning?
The effect of electricity in the clouds. A flash of lightning is simply a stream of the electric fluid passing from the clouds to the earth, from the earth to the clouds, or from one cloud to another. Lightning usually strikes the highest and most pointed objects, as high hills, trees, spires, masts of ships, &c.
What is Thunder?
The report which accompanies the electrical union of the clouds: or the echoes of the report between them and the earth. Thunder is caused by a sudden discharge of electrical matter collected in the air, by which vibrations are produced, which give rise to the sound.
What is Electricity?
One of those agents passing through the earth and all substances, without giving any outward signs of its presence, when at rest; yet when active, often producing violent and destructive effects. It is supposed to be a highly elastic fluid, capable of moving through matter. Clouds owe their form and existence, probably, to it; and it passes through all substances, but more easily through metals, water, the human body, &c., which are called conductors, than through air, glass, and silk, which are called _non_-conductors. When bodies are not surrounded with non-conductors, the electricity escapes quickly into the earth.
To what part of bodies is Electricity confined?
To their surfaces, as the outside may be electric, and the inside in a state of neutrality. The heat produced by an electric shock is very powerful, but is only accompanied by light when the fluid is obstructed in its passage. The production and condensation of vapor is a great source of the atmospheric electricity.
Condensation, the act of making any body dense or compact; that is, of bringing its parts into closer union.
In what other sense is the term Electricity employed?
This term is also employed to designate that important branch of knowledge which relates to the properties shown by certain bodies when rubbed against, or otherwise brought in contact with, each other, to attract substances, and emit sparks of fire.
Designate, to point out by some particular token.
Emit, to send forth, to throw out.
[Illustration: CUTTING AND GATHERING ICE, ON THE HUDSON RIVER, NEW YORK.]
Whence is the