High upper clouds crossing the sun, moon, or stars, in a direction different from that of the lower clouds, or of the wind then blowing below, foretell a change of wind toward their direction, except between the Tropics or in the regions of the Trade Winds, where there is generally an upper and counter current of air, with very light clouds, which is not an indication of any approaching change.

Dew is an indication of fine weather, its formation never begins under an overcast sky, or when there is much wind.

Remarkable clearness of the atmosphere near the horizon; distant objects, such as hills, unusually visible or well defined; and what is called "a good hearing day," may be mentioned among signs of rain, if not wind.

More than usual twinkling of the stars, indistinctness or apparent multiplication of the moon's horns, haloes, "wind-dogs, "and the rainbow, are more or less significant of increasing wind, if not approaching rain, with or without wind.

The "young moon with the old moon in her arms" is a sign of bad weather in the temperate zones.

Much refraction is a sign of easterly wind.

After very warm and calm weather a storm is likely to follow; or at any time when the atmosphere is heated much above the average temperature.

When sea birds fly out early and far to seaward, moderate wind and fair weather may be expected.

An officer of a watch, with a good eye for clouds and signs of changing weather, may save his men a great deal of unnecessary exposure, as well as work, besides economising sails, spars, and rigging, to an extent often too little appreciated.

WEATHER SIGNS.

Whether clear or cloudy.—In the Evening.

A rosy sky foretells fine weather.

A dark, dull red sky foretells rain.

A bright yellow sky foretells wind.
A pale yellow sky foretells rain.

A tawny or coppery sky foretells wind.

A sickly greenish sky foretells wind and rain.

Whether clear or cloudy.-In the Morning.

A grey sky foretells fine weather.

A red sky foretells much wind and perhaps rain.
A dark, gloomy blue sky foretells wind.

A light, bright blue sky foretells fine weather.

Thus, by the preponderance of red, yellow, green, grey, or other tints, the coming weather may be foretold with considerable accuracy.

A high dawn (that is, when the first indications of daylight are seen above a bank of clouds) foretells wind.

A low dawn (that is, when the first indications of daylight are seen very low on the horizon) foretells fine

weather.

Soft delicate-looking clouds foretell fine weather.
Hard-edged oily-looking clouds foretell wind.

Generally, the softer the clouds appear, the less wind (but perhaps more rain) may be expected; and the harder, more greasy, rolled, tufted or ragged they appear, the stronger the coming wind will prove.

Light, delicate, quiet tints or colours, with soft, undefined forms of clouds, indicate and accompany fine weather; but gaudy or unusual hues, with hard, definitely-outlined clouds, foretell rain and probably strong wind.

High upper clouds crossing the sun, moon, or stars, in a direction different from that of the lower clouds, or of the wind then blowing below, foretell a change of wind toward their direction, except between the Tropics or in the regions of the Trade Winds, where there is generally an upper and counter current of air, with very light clouds, which is not an indication of any approaching change.

Dew is an indication of fine weather, its formation never begins under an overcast sky, or when there is much wind.

Remarkable clearness of the atmosphere near the horizon; distant objects, such as hills, unusually visible or well defined; and what is called "a good hearing day," may be mentioned among signs of rain, if not wind.

More than usual twinkling of the stars, indistinctness or apparent multiplication of the moon's horns, haloes, wind-dogs, "and the rainbow, are more or less significant of increasing wind, if not approaching rain, with or without wind.

The "young moon with the old moon in her arms is a sign of bad weather in the temperate zones.

Much refraction is a sign of easterly wind.

After very warm and calm weather a storm is likely to follow; or at any time when the atmosphere is heated much above the average temperature.

When sea birds fly out early and far to seaward, moderate wind and fair weather may be expected.

An officer of a watch, with a good eye for clouds and signs of changing weather, may save his men a great deal of unnecessary exposure, as well as work, besides economising sails, spars, and rigging, to an extent often too little appreciated.

WEATHER GLASSES.

The Barometer shows the pressure of the atmosphere. The Thermometer shows the temperature of the atmosphere.

The Hygrometer shows the dampness of the atmosphere.

In South Latitude read South for North.

The Barometer RISES, for northerly wind (including from north-west by the north, to the eastward), for dry or less wet weather, for less wind,-or for more than one of these changes; except on a few occasions when rain, hail, or snow comes from the northward with strong wind.

A Thermometer FALLS, for change of wind toward northerly directions.

The Barometer FALLS, for southerly wind (including from south-east by the south, to the westward), for wet weather, for stronger wind,

-or for more than one of these changes; except on a few occasions when moderate wind with rain or snow comes from the northward.

A Thermometer RISES, for change of wind toward southerly directions.

Moisture or dampness in the atmosphere, as shown by the Hygrometer, increases before rain, fog or dew.

The air of the Polar or Northerly current has been chilled, and is heavy, cold and dry; therefore while it is blowing, the Barometer is high and the weather usually dry.

The air of the Equatorial or Southerly current has been heated, and is light, warm, and moist; therefore while it is blowing, the Barometer is low and the weather usually wet.

Electricity in the atmosphere, thunder or lightning. do not affect the Aneroid or a Mercurial Barometer.

DESCRIPTION OF THE BAROMETER.

The Barometer consists of a straight glass tube about 34 inches in length, closed at one end, and filled with pure mercury; it is placed upright, with the open end down, in a small cup or cistern partially filled with mercury exposed to atmospheric pressure.

The mercury in the tube sinks, thereby causing a vacuum to be formed in the upper part of the tube, until the top of the column stands at an average height of nearly 30 inches above the surface of the mercury in the cistern.

The pressure which the column of mercury exerts at its base is quite independent of the diameter or capacity of the tube, but depends entirely on the height of the column, which rises or falls as the atmosphere becomes heavier or lighter and presses with more or less weight on the mercury in the cistern.

When the Barometer is at the sea level, the weight or pressure of the atmosphere is about 15 pounds on a square inch of surface; but a cubic inch of mercury weighs about half a pound, therefore, assuming the sectional area of the tube to be equal to a square inch, a column 30 inches in height will contain 30 cubic inches of mercury and exert a pressure at its base equal to a weight of 15 pounds, so that the column of mercury in the tube is held in equilibrium by the pressure of the atmosphere on the mercury in the cistern; hence the susceptibility of the instrument, and its power to indicate the slightest change in the condition of the atmosphere.

The column FALLS fully a tenth of an inch for every 100 feet of elevation above the sea level, and RISES fully a tenth of an inch for every 100 feet of depression below the sea level, because there is a less head or weight of air above it in the one case and a greater in the other.