most frequently happen in warm latitudes; the wind blows, from every way, towards both; and a water-spout has been known to move from the sea to the land, and to produce all the effects of a whirlwind. They are both, probably, the effects of the electrical fluid.

VAPORS AND CLOUDS.

VAPORS are raised from the surface of the moist earth and waters, the principal cause of which is, probably, the heat of the sun; the evaporation being always greatest when the heat is greatest. The vapors, thus raised, by heat, ascend into the cold regions of the atmosphere, and form Clouds, which are of the same nature as dews and fogs upon the earth.

When the water in the air ceases to be suspended, it falls down, and the particles, uniting in falling, form drops, or Rain. If it be very cold in those regions where the rain begins to be formed, it then descends in Snow. When the drops of rain are formed, and are descending, if in their descent they pass through a region of the air cold enough to freeze them, they descend in Hail.

ELECTRICITY.

The earth and all bodies, with which we are acquainted, are supposed to contain a certain quantity of an exceedingly elastic fluid, called the Electric fluid.

Lightning is the electric fluid in the atmosphere; discharging itself, sometimes from one cloud to another, and sometimes from the clouds to the earth. This discharge occasions the awful roll, or sound, called Thunder.

A machine, fitted up with certain appurtenances, for the purpose of exciting electric fluid, and making it perceptible to the senses, is called an Electrical machine. The sudden discharge of the fluid contained in the machine, gives a painful sensation to any animal placed within the circuit of its communication, called the Electrical Shock.

That lightning and the electric fluid are one and the same substance, has been proved by Dr. Franklin and others. Lightning strikes the highest and most pointed objects; rends bodies to pieces and sets them on fire; dis

solves metals; and destroys animal life; in all which, it agrees with the phenomena produced by an electrical apparatus.

Some fishes have the power of giving shocks, similar to those of artificial electricity. The torpedo, found in the rivers of South-America, when touched by the naked hand, or any conductor, produces a strong, electric shock. The gymnotus electricus, and some others, possess the same power. Electricity has been administered for various diseases of the human body; some of which have been relieved, and others perfectly cured.

LIGHT.

LIGHT is that, which, proceeding from a certain body to the eye, produces the perception of seeing. An exceedingly small portion of light, is called a Ray. A larger body of light consisting of many parallel rays, is called a Beam.

The rays of light fly with amazing swiftness, at the rate, it is computed, of 11,875,000 miles in a minute or more than a million times swifter than a cannon ball, which is computed to move 8 miles in a minute. Light is found to proceed from both animal and vegetable substances in a putrid state.

The Twilig is that faint light, which appears in the east in the morning before the sun rises, and gradually vanishes in the west after he sets.

The sun is the original source of light to our system; and though it rise and set all over the earth, yet the circumstances attending its rising and setting are very different in different countries.

In the equatorial regions, darkness comes on very soon after sunset; because the convexity of the earth comes quickly between the sun and the eye of the observer. Proceeding from the equator, the twilight continues a longer time after sunset; and, in 48° N. latitude, it continues through the night in the month of June. As we approach the poles, the twilight becomes brighter and brighter, till at last the sun does not appear to touch the horizon, but is seen above it many days successively. On the other hand, in winter, the sun sinks lower and lower, till it does

not appear at all, and there is only a dim twilight, for an hour or two, in the middle of the day.

Notwithstanding the seeming inequality in the distribution of light and darkness, it is certain that, throughout the whole world, there is nearly an equal proportion of light diffused on every part, abstracted from what is absorbed by clouds, vapors, and the atmosphere itself. The equatorial regions have indeed the most intense light dur ing the day, but the nights are long and dark; while, on the other hand, in the northerly and southerly parts, though the sun shines less powerfully, yet the length of time that he appears above the horizon, with the greater duration of twilight, make up for the seeming deficiency.

THE HARVEST MOON.

It is a remarkable and highly beneficial circumstance, that in those countries which are at considerable distances from the equator and the poles, the autumnal full moons, rise nearly at sunset, from the first to the third quarter; a dispensation singularly calculated to facilitate the reaping and gathering in the fruits of the earth. This phenomenon is called the Harvest Moon. It is farther observable, that this appearance in the autumnal months is peculiar to the full moon; for though, in every month, the moon for several successive days will vary the time of her rising very little; yet in the vernal months, this happens at the time of the new moon; in the winter months, about the time of the first quarter; and in summer, at the time of the last quarter. In the latitude of 30° north, the time of the moon's rising is observed to vary only two hours in six days.

NORTHERN LIGHT.

No

The Aurora Borealis, or Northern Light, in many parts of the northern hemisphere, enables the inhabitants to pursue their occupations during the absence of the sun. satisfactory conjecture has yet been formed, as to the cause of this phenomenon. Some have supposed it to be electrical matter, imbibed by the earth from the sun, in the

warm latitudes, and passing off through the upper regions of the atmosphere, to the place whence it came,

These lights commonly appear at twilight, near the horizon, of a dun color, approaching to yellow, and sometimes continue in that state for several hours, without any apparent motion. In the Shetland Isles, and other northern regions, they are the constant attendants of clear evenings, and prove a great relief amid the gloom of long winter nights; and are there called Merry Dancers. They sometimes break out into streams of strong light, spreading into columns, and altering slowly into thousands of different shapes varying their colours, from all the tints of yellow, to the most obscure russet. They often cover the whole hemisphere, affording a most brilliant prospect. At other times, they assume the color of blood, and make a very dreadful appearance. They have generally a quick tremulous motion, which continues till the whole vanishes,

HEAT AND COLD.

The presence of the sun is one of the principal sources of heat, and its absence the cause of cold. But, were these the only sources of heat and cold, there would be, in the same parallels of latitude, the same degree of heat and cold, at the same season; which is not the fact; for very hot days are frequently felt in the coldest climates and very cold weather, and even perpetual snow, is found in countries under the equator.

One source is from the earth; probably arising from a mass of heat diffused through it, which, imparted from the -earth to the atmosphere, tends greatly to moderate the severity of the winter's cold. It is probably from this internal heat, that snow generally begins to melt first at the bottom. Another source of heat is the condensation of vapor, which warms the surrounding atmosphere. This condensation is frequently formed by the attraction of an electrical cloud and hence the great sultriness often experienced before a storm.

As the earth is a source of heat, so distance from it is a source of cold; and it is found in ascending the atmo. sphere, that the cold increases. The tops of the highest

mountains, even under the equator, are continually covered with snow.

The same cause, which makes condensation a source of heat, makes evaporation a source of cold; as it absorbs the fire in the latter instance, which it gives out in the former.

The instrument made use of in measuring the different degrees of heat and cold in the atmosphere, is called a Thermometer.

The action of freezing is always instantaneous. Ice is lighter than the same bulk of water, and this is the reason of its floating upon the surface. Boiled water is more easily frozen, than that which has not been boiled; and that which is a little agitated, than that which is entirely

at rest.

POLITICAL DIVISIONS OF THE EARTH.

The habitable parts of the globe are divided into what are commonly, though very inaccurately, called FOUR QUARTERS, which, according to their magnitude, may be ranked as follows; America, Asia, Africa, Europe.

Of these divisions, Europe is the smallest, but the most improved and civilized; Africa the most barbarous, and the least known; Asia the wealthiest, and the most anciently inhabited, America the largest, the grandest, as to its mountains and rivers, the least populous and wealthy, the last explored and inhabited.

Subdivisions. These grand divisions of the globe, for the purposes of government, &c. are subdivided into innumerable districts, or portions, of various extent, and under various names; as Empires, Kingdoms, Republics, States, Departments, Principalities, Dukedoms, Dutchies, Counties, Cities, Townships, Parishes, &c. Different nations have different names for these divisions, but they mean much the same thing.

Several countries, or principalities, with different governments, confederated under one sovereign or head, is called an EMPIRE; as the German Empire, which is composed of about 300 principalities; and the Russian Empire, which includes many extensive countries, that are divided into 42 different governments, combined under an Emperor, who is the head of the Empire.