VELOCITY OF CLOUDS.—This is of two kinds: 1st. Velocity of Propagation; and 2nd. Velocity of Motion. The first occurs when at a given altitude the dew-point is suddenly attained, when the sky on one occasion was covered from the eastern to the western horizon at the rate of 300 miles per hour. The second is dependent on the force of atmospheric currents, which is much greater in the upper regions of the air than in those nearer the earth. Accurate observations of the shadows of clouds, borne across the fields on a summer’s day, warrant the assertion that an apparently slow motion of clouds is equal to eighty miles an hour, while a velocity of 120 miles is attained without impressing the observer with the idea of rapidity. On the subject of clouds Admiral Fitzroy says:— May be Expected ----- Fine weather When clouds are “soft-looking or delicate.” Wind When clouds are hard-edged or oily-looking. Less wind In proportion as the clouds look _softer_. More wind The harder, more “greasy,” rolled, tufted, or ragged the clouds look. Rain When small-inky-looking clouds appear. Wind _and_ rain When light scud clouds are seen driving across heavy masses. Wind only When light scud clouds are seen alone. Change of wind When high upper clouds cross the sun, moon, or stars in a direction different from that of the lower clouds, or the wind then felt below. Wind With tawny or copper-coloured clouds. The following “Weather Warnings” may be gathered from the COLOUR OF THE SKY:— Whether clear or cloudy, a rosy sky at sunset presages fine weather; a sickly greenish hue, wind and rain; a red sky in the morning, bad weather, or much wind or rain; a grey sky in the morning, fine weather; a high dawn (_i. e._, when the first indications of daylight are seen above a bank of clouds), wind; a low dawn (_i. e._, when the day breaks on or near the horizon), fair weather. Light, delicate, quiet tints or colours, with soft, indefinite forms of clouds, indicate and accompany fine weather; but gaudy or unusual hues, with hard, definitely outlined clouds, foretell rain and probably strong wind. Also a bright yellow sky at sunset presages wind; a pale yellow, wet; orange or copper-coloured, wind and rain: and thus, by the prevalence of red, yellow, green, grey, or other tints, the coming weather may be told very nearly; indeed, if aided by instruments, almost exactly. After fine, clear weather the first signs in a sky of a coming change are usually light streaks, curls, wisps, or mottled patches of white distant cloud, which increase and are followed by an overcasting of murky vapour that grows into cloudiness. This appearance, more or less oily or watery as wind or rain will prevail, is an infallible sign.