=State of the Sky.=——By the _state of the sky_ is meant the condition of the sky as to its cloudiness. Clouds add much to the beauty and variety of nature. They are often gorgeously colored at sunset. By their changes in form, color, and amount from day to day they relieve what might otherwise be a wearisome succession of the same weather types. Prevailingly overcast skies have a depressing effect. Prevailingly clear skies become monotonous. A proper amount of bright sunshine is essential for the ripening of crops, but too much sunshine may parch soil and vegetation, and become injurious. Clouds bring rain; hence a sufficient amount of cloudiness is just as necessary as a sufficient amount of sunshine. The drift of clouds shows us the direction of movement of the air above us, and is of considerable help in forecasting the weather. Fog, which is a very low cloud, is in some cases so common as to be a meteorological element of great importance. In the city of London, where fogs are very prevalent, especially in winter, the average number of hours of bright sunshine in December and January is only fifteen in each month. The London fogs are, in great part, due to the presence in the air of vast numbers of particles of soot and smoke from millions of fires. These particles increase the density of the fog and prolong its duration. The amount of cloudiness is recorded on a scale of _tenths_. A _clear_ sky is one that is less than 3/10 cloudy; a _fair_ sky is from 3/10 to 7/10 cloudy; and a _cloudy_ sky is over 7/10 cloudy. In observing the state of the sky, note such points as the times of clouding and of clearing; the arrangement of the clouds, _i.e._, whether they are few and scattered, or cover the sky with a uniform layer; the common forms of clouds; the changes in the amounts of cloudiness, etc. Another new column must be added in the record book for the cloudiness. The table will now appear thus:—— SAMPLE RECORD OF TEMPERATURE, WIND, AND STATE OF THE SKY.