Notes and Queries, Number 206, October 8, 1853. Various

Чтение книги онлайн.

      There are composite forms of cloud, varieties of the above, which need not be noticed here. The Cumulus is the parent cloud, and produces every other form of cloud known, or which can exist. Mountain ranges and currents of air of unequal temperatures may produce visible vapour, but not true cloud.

      Cumulus. This cloud is always formed at "the dew point." The vapour of the lower atmosphere, at this elevation, is condensed, or rendered visible. In fog the dew point is at the surface of the earth; in summer it may be several thousands of feet above. The Cumulus cloud forms from below. The invisible vapour of the lower atmosphere is condensed, parts with its thousand degrees of latent heat, which rush upwards, forcing the vapour into the vast hemispherical heaps of snowy, glittering clouds, which, seen in midday, appear huge mountains of clouds; the "cloud-land" of the poet, floating in liquid air. The Cumulus cloud is ever changing in form. Cumulating from a level base, the top is mounting higher and higher, until the excessive moisture is precipitated in heavy rain, hail, or thunder showers.

      The tops of the Cumulus, carried away by the upper equatorial currents, form the Cirrus clouds, which clouds must be frozen vapour, as they are generally from twenty to thirty thousand feet above the level of the sea. The base of the Cumulus is probably never more, in England, than five thousand feet high, rarely this. The Nimbus is the Cumulus shedding its vapour in rain; and the Stratus is the partially exhausted and fading Nimbus.

      Poets in all ages have watched the clouds with interest; and Shakspeare has not only correctly described them, but has, in metaphor, used them in some of his sublimest passages. Ariel will "ride on the curled clouds" to Prospero's "strong bidding task" that is, ride on the highest Cirrus cloud, in regions impassable to man. How admirably the raining Cumulus (Nimbus cloud) is described in the same play:

      Hamlet points to a changing Cumulus cloud, when he says to Polonius, "Do you see that cloud, that almost in shape like a camel?"

      But the finest cloud passage in the whole range of literature is contained in Antony and Cleopatra, painting, as it does, the fallen and wasting state of the emperor (Act IV. Sc. 12.):

      Those who wish to understand this sublime passage must watch a bank of Cumulus clouds at the western sky on a summer's evening. The tops of the clouds must not be more than five or ten degrees above the apparent horizon. There must also be a clear space upwards, and the sun fairly set to the last stages of twilight. It will then be comprehended as to what is meant by "black vesper's pageants," and Warton and Knight will no more mislead by their note. It is only at "black vespers" that such a pageant can be seen, when the liberated heat of the Cumulus cloud is forcing the vapour into the grand or fantastic shapes indicated to the poet's eye and mind.

      How truly does Antony read his own condition in the changing and perishable clouds. Shakspeare names or alludes to the clouds in more than one hundred passages, and the form of cloud is ever correctly indicated. Who does not remember the passages in Romeo and Juliet? Much more might be written on this subject.

      At the Hull meeting of the British Association, Mr. Russell, farmer, Kilwhiss, Fife, read a paper on "The Action of the Winds which veer from the South-west to West, and North-west to North." This he wound up by a reference to Shakspeare, which may be worthy of noting: