We so rarely now see cumulus cloud of this grand kind, that I will yet delay you by reading the description of its nearer aspect, in the 'Eagle's Nest.'
"The rain which flooded our fields the Sunday before last, was followed, as you will remember, by bright days, of which Tuesday the 20th (February, 1872) was, in London, notable for the splendor, towards the afternoon, of its white cumulus clouds. There has been so much black east wind lately, and so much fog and artificial gloom, besides, that I find it is actually some two years since I last saw a noble cumulus cloud under full light. I chanced to be standing under the Victoria Tower at Westminster, when the largest mass of them floated past, that day, from the northwest; and I was more impressed than ever yet by the awfulness of the cloud-form, and its unaccountableness, in the present state of our knowledge. The Victoria Tower, seen against it, had no magnitude: it was like looking at Mont Blanc over a lamp-post. The domes of cloud-snow were heaped as definitely: their broken flanks were as gray and firm as rocks, and the whole mountain, of a compass and height in heaven which only became more and more inconceivable as the eye strove to ascend it, was passing behind the tower with a steady march, whose swiftness must in reality have been that of a tempest: yet, along all the ravines of vapor, precipice kept pace with precipice, and not one thrust another.
"What is it that hews them out? Why is the blue sky pure there,—the cloud solid here; and edged like marble: and why does the state of the blue sky pass into the state of cloud, in that calm advance?
"It is true that you can more or less imitate the forms of cloud with explosive vapor or steam; but the steam melts instantly, and the explosive vapor dissipates itself. The cloud, of perfect form, proceeds unchanged. It is not an explosion, but an enduring and advancing presence. The more you think of it, the less explicable it will become to you."
Thus far then of clouds that were once familiar; now at last, entering on my immediate subject, I shall best introduce it to you by reading an entry in my diary which gives progressive description of the most gentle aspect of the modern plague-cloud.
"Bolton Abbey, 4th July, 1875.
Half-past eight, morning; the first bright morning for the last fortnight.
At half-past five it was entirely clear, and entirely calm; the moorlands glowing, and the Wharfe glittering in sacred light, and even the thin-stemmed field-flowers quiet as stars, in the peace in which—
'All trees and simples, great and small,
That balmy leaf do bear,
Than they were painted on a wall,
No more do move, nor steir.'