PREFACE
The following lectures, drawn up under the pressure of more imperative and quite otherwise directed work, contain many passages which stand in need of support, and some, I do not doubt, more or less of correction, which I always prefer to receive openly from the better knowledge of friends, after setting down my own impressions of the matter in clearness as far as they reach, than to guard myself against by submitting my manuscript, before publication, to annotators whose stricture or suggestion I might often feel pain in refusing, yet hesitation in admitting.
But though thus hastily, and to some extent incautiously, thrown into form, the statements in the text are founded on patient and, in all essential particulars, accurately recorded observations of the sky, during fifty years of a life of solitude and leisure; and in all they contain of what may seem to the reader questionable, or astonishing, are guardedly and absolutely true.
In many of the reports given by the daily press, my assertion of radical change, during recent years, in weather aspect was scouted as imaginary, or insane. I am indeed, every day of my yet spared life, more and more grateful that my mind is capable of imaginative vision, and liable to the noble dangers of delusion which separate the speculative intellect of humanity from the dreamless instinct of brutes: but I have been able, during all active work, to use or refuse my power of contemplative imagination, with as easy command of it as a physicist's of his telescope: the times of morbid are just as easily distinguished by me from those of healthy vision, as by men of ordinary faculty, dream from waking; nor is there a single fact stated in the following pages which I have not verified with a chemist's analysis, and a geometer's precision.
The first lecture is printed, with only addition here and there of an elucidatory word or phrase, precisely as it was given on the 4th February. In repeating it on the 11th, I amplified several passages, and substituted for the concluding one, which had been printed with accuracy in most of the leading journals, some observations which I thought calculated to be of more general interest. To these, with the additions in the first text, I have now prefixed a few explanatory notes, to which numeral references are given in the pages they explain, and have arranged the fragments in connection clear enough to allow of their being read with ease as a second Lecture.
Herne Hill, 12th March, 1884.
THE STORM-CLOUD OF THE NINETEENTH
CENTURY
Let me first assure my audience that I have no arrière pensée in the title chosen for this lecture. I might, indeed, have meant, and it would have been only too like me to mean, any number of things by such a title;—but, to-night, I mean simply what I have said, and propose to bring to your notice a series of cloud phenomena, which, so far as I can weigh existing evidence, are peculiar to our own times; yet which have not hitherto received any special notice or description from meteorologists.
So far as the existing evidence, I say, of former literature can be interpreted, the storm-cloud—or more accurately plague-cloud, for it is not always stormy—which I am about to describe to you, never was seen but by now living, or lately living eyes. It is not yet twenty years that this—I may well call it, wonderful, cloud has been, in its essence, recognizable. There is no description of it, so far as I have read, by any ancient observer. Neither Homer nor Virgil, neither Aristophanes nor Horace, acknowledge any such clouds among those compelled by Jove. Chaucer has no word of them, nor Dante;1 Milton none, nor Thomson. In modern times, Scott, Wordsworth and Byron are alike unconscious of them; and the most observant and descriptive of scientific men, De Saussure, is utterly silent concerning them. Taking up the traditions of air from the year before Scott's death, I am able, by my own constant and close observation, to certify you that in the forty following years (1831 to 1871 approximately—for the phenomena in question came on gradually)—no such clouds as these are, and are now often for months without intermission, were ever seen in the skies of England, France, or Italy.
In those old days, when weather was fine, it was luxuriously fine; when it was bad—it was often abominably bad, but it had its fit of temper and was done with it—it didn't sulk for three months without letting you see the sun,—nor send you one cyclone inside out, every Saturday afternoon, and another outside in, every Monday morning.
In fine weather the sky was either blue or clear in its light; the clouds, either white or golden, adding to, not abating, the luster of the sky. In wet weather, there were two different species of clouds,—those of beneficent rain, which for distinction's sake I will call the non-electric rain-cloud, and those of storm, usually charged highly with electricity. The beneficent rain-cloud was indeed often extremely dull and gray for days together, but gracious nevertheless, felt to be doing good, and often to be delightful after drought; capable also of the most exquisite coloring, under certain conditions;2 and continually traversed in clearing by the rainbow:—and, secondly, the storm-cloud, always majestic, often dazzlingly beautiful, and felt also to be beneficent in its own way, affecting the mass of the air with vital agitation, and purging it from the impurity of all morbific elements.
In the entire system of the Firmament, thus seen and understood, there appeared to be, to all the thinkers of those ages, the incontrovertible and unmistakable evidence of a Divine Power in creation, which had fitted, as the air for human breath, so the clouds for human sight and nourishment;—the Father who was in heaven feeding day by day the souls of His children with marvels, and satisfying them with bread, and so filling their hearts with food and gladness.
Their hearts, you will observe, it is said, not merely their bellies,—or indeed not at all, in this sense, their bellies—but the heart itself, with its blood for this life, and its faith for the next. The opposition between this idea and the notions of our own time may be more accurately expressed by modification of the Greek than of the English sentence. The old Greek is—
ἐμπιπλῶν τροφῆς καὶ ἐυφροσύνης
τὰς καρδίας ήμῶν.
filling with meat, and cheerfulness, our hearts. The modern Greek should be—
ἐμπιπλῶν ἀνέμου καὶ ἀφροσύνης
τὰς γαστέρας ἡμῶν.
filling with wind, and foolishness, our stomachs.
You will not think I waste your time in giving you two cardinal examples of the sort of evidence which the higher forms of literature furnish respecting the cloud-phenomena of former times.
When, in the close of my lecture on landscape last year at Oxford, I spoke of stationary clouds as distinguished from passing ones, some blockheads wrote to the papers to say that clouds never were stationary. Those foolish letters were so far useful in causing a friend to write me the pretty one I am about to read to you, quoting a passage about clouds in Homer which I had myself never noticed, though perhaps the most beautiful of its kind in the Iliad. In the fifth book, after the truce is broken, and the aggressor Trojans are rushing to the onset in a tumult of clamor and charge, Homer says that the Greeks, abiding them "stood like clouds." My correspondent, giving the passage, writes as follows:—
"Sir,—Last winter when I was at Ajaccio, I was one day reading Homer by the open window, and came upon the lines—
Ἀλλ᾽ ἔμενον, νεφέλῃσιν ἐοικότες ἅς τε Κρονίων
Νηνεμίης ἔστησεν ἐπ᾽ ἀκροπόλοισιν ὄρεσσιν,
Ἀτρέμας, ὄφρ᾽ εὕδῃσι μένος Βορέαο καὶ ἄλλων
Ζαχρειῶν ἀνέμων, οἵ τε νέφεα σκιόεντα
Πνοιῇσιν λυγυρῇσι διασκιδνᾶσιν ἀέντες‧
Ὡσ Δαναοὶ Τρῶας μένον ἔμπεδον, οὐδ᾽ ἐφέβοντο.
'But they stood, like the clouds which the Son of Kronos stablishes in calm upon the mountains, motionless, when the rage of the North and of all the fiery winds is asleep.' As I finished these lines, I raised my eyes, and looking across the gulf, saw a long line of clouds resting on the top of its hills. The day was windless, and there they stayed, hour after hour, without any stir or motion. I remember how I was delighted at the time, and have often since that day thought on the beauty and the truthfulness of Homer's simile.
"Perhaps this little fact may interest you, at a time when you are attacked for your description of clouds.
"I am, sir, yours faithfully,
G. B. Hill."
With this bit of noonday from Homer, I will read you a sunset and a sunrise from Byron. That will enough express to you the scope and sweep of all glorious literature, from the orient of Greece herself to the death of the last Englishman who loved her.3 I will read you from 'Sardanapalus' the address of the Chaldean priest Beleses to the sunset, and of the Greek slave, Myrrha, to the morning.
"The sun goes down: methinks he sets more slowly,
Taking his last look of Assyria's empire.
How red he glares amongst those deepening clouds,4
Like the blood he predicts.5 If not in vain,
Thou sun that sinkest, and ye stars which rise,
I have outwatch'd ye, reading ray by ray
The edicts of your orbs, which make Time tremble
For what he brings the nations, 't is the furthest
Hour of Assyria's years. And yet how calm!
An earthquake should announce so great a fall—
A summer's sun discloses it. Yon disk
To the star-read Chaldean, bears upon
Its everlasting page the end of what
Seem'd everlasting; but oh! thou true sun!
The burning oracle of all that live,
As fountain of all life, and symbol of
Him who bestows it, wherefore dost thou limit
Thy lore unto calamity?6 Why not
Unfold the rise of days more worthy thine
All-glorious burst from ocean? why not dart
A beam of hope athwart the future years,
As of wrath to its days? Hear me! oh, hear me!
I am thy worshiper, thy priest, thy servant—
I have gazed on thee at thy rise and fall,
And bow'd my head beneath thy mid-day beams,
When my eye dared not meet thee. I have watch'd
For thee, and after thee, and pray'd to thee,
And sacrificed to thee, and read, and fear'd thee,
And ask'd of thee, and thou hast answer'd—but
Only to thus much. While I speak, he sinks—
Is gone—and leaves his beauty, not his knowledge,
To the delighted west, which revels in
Its hues of dying glory. Yet what is
Death, so it be but glorious? 'T is a sunset;
And mortals may be happy to resemble
The gods but in decay."
Thus the Chaldean priest, to the brightness of the setting sun. Hear now the Greek girl, Myrrha, of his rising.
"The day at last has broken. What a night
Hath usher'd it! How beautiful in heaven!
Though varied with a transitory storm,
More beautiful in that variety:7
How hideous upon earth! where peace, and hope,
And love, and revel, in an hour were trampled
By human passions to a human chaos,
Not yet resolved to separate elements:—
'T is warring still! And can the sun so rise,
So bright, so rolling back the clouds into
Vapors more lovely than the unclouded sky,
With golden pinnacles, and snowy mountains,
And billows purpler than the ocean's, making
In heaven a glorious mockery of the earth,
So like,—we almost deem it permanent;
So fleeting,—we can scarcely call it aught
Beyond a vision, 't is so transiently
Scatter'd along the eternal vault: and yet
It dwells upon the soul, and soothes the soul,
And blends itself into the soul, until
Sunrise and sunset form the haunted epoch
Of sorrow and of love."
How often now—young maids of London,—do you make sunrise the 'haunted epoch' of either?
Thus much, then, of the skies that used to be, and clouds "more lovely than the unclouded sky," and of the temper of their observers. I pass to the account of clouds that are, and—I say it with sorrow—of the distemper of their observers.
But the general division which I have instituted between bad-weather and fair-weather clouds must be more carefully carried out in the sub-species, before we can reason of it farther: and before we begin talk either of the sub-genera and sub-species, or super-genera and super-species of cloud, perhaps we had better define what every cloud is, and must be, to begin with.
Every cloud that can be, is thus primarily definable: "Visible vapor of water floating at a certain height in the air." The second clause of this definition, you see, at once implies that there is such a thing as visible vapor of water which does not float at a certain height in the air. You are all familiar with one extremely cognizable variety of that sort of vapor—London Particular; but that especial blessing of metropolitan society is only a strongly-developed and highly-seasoned condition of a form of watery vapor which exists just as generally and widely at the bottom of the air, as the clouds do—on what, for convenience' sake, we may call the top of it;—only as yet, thanks to the sagacity of scientific men, we have got no general name for the bottom cloud, though the whole question of cloud nature begins in this broad fact, that you have one kind of vapor that lies to a certain depth on the ground, and another that floats at a certain height in the sky. Perfectly definite, in both cases, the surface level of the earthly vapor, and the roof level of the heavenly vapor, are each of them drawn within the depth of a fathom. Under their line, drawn for the day and for the hour, the clouds will not stoop, and above theirs, the mists will not rise. Each in their own region, high or deep, may expatiate at their pleasure; within that, they climb, or decline,—within that they congeal or melt away; but below their assigned horizon the surges of the cloud sea may not sink, and the floods of the mist lagoon may not be swollen.
That is the first idea you have to get well into your minds concerning the abodes of this visible vapor; next, you have to consider the manner of its visibility. Is it, you have to ask, with cloud vapor, as with most other things, that they are seen when they are there, and not seen when they are not there? or has cloud vapor so much of the ghost in it, that it can be visible or invisible as it likes, and may perhaps be all unpleasantly and malignantly there, just as much when we don't see it, as when we do? To which I answer, comfortably and generally, that, on the whole, a cloud is where you see it, and isn't where you don't; that, when there's an evident and honest thundercloud in the northeast, you needn't suppose there's a surreptitious and slinking one in the northwest;—when there's a visible fog at Bermondsey, it doesn't follow there's a spiritual one, more than usual, at the West End: and when you get up to the clouds, and can walk into them or out of them, as you like, you find when you're in them they wet your whiskers, or take out your curls, and when you're out of them, they don't; and therefore you may with probability assume—not with certainty, observe, but with probability—that there's more water in the air where it damps your curls than where it doesn't. If it gets much denser than that, it will begin to rain; and then you may assert, certainly with safety, that there is a shower in one place, and not in another; and not allow the scientific people to tell you that the rain is everywhere, but palpable in Tooley Street, and impalpable in Grosvenor Square.
That, I say, is broadly and comfortably so on the whole,—and yet with this kind of qualification and farther condition in the matter. If you watch the steam coming strongly out of an engine-funnel,8—at the top of the funnel it is transparent,—you can't see it, though it is more densely and intensely there than anywhere else. Six inches out of the funnel it becomes snow-white,—you see it, and you see it, observe, exactly where it is,—it is then a real and proper cloud. Twenty yards off the funnel it scatters and melts away; a little of it sprinkles you with rain if you are underneath it, but the rest disappears; yet it is still there;—the surrounding air does not absorb it all into space in a moment; there is a gradually diffusing current of invisible moisture at the end of the visible stream—an invisible, yet quite substantial, vapor; but not, according to our definition, a cloud, for a cloud is vapor visible.
Then the next bit of the question, of course, is, What makes the vapor visible, when it is so? Why is the compressed steam transparent, the loose steam white, the dissolved steam transparent again?
The scientific people tell you that the vapor becomes visible, and chilled, as it expands. Many thanks to them; but can they show us any reason why particles of water should be more opaque when they are separated than when they are close together, or give us any idea of the difference of the state of a particle of water, which won't sink in the air, from that of one that won't rise in it?9
And here I must parenthetically give you a little word of, I will venture to say, extremely useful, advice about scientific people in general. Their first business is, of course, to tell you things that are so, and do happen,—as that, if you warm water, it will boil; if you cool it, it will freeze; and if you put a candle to a cask of gunpowder, it will blow you up. Their second, and far more important business, is to tell you what you had best do under the circumstances,—put the kettle on in time for tea; powder your ice and salt, if you have a mind for ices; and obviate the chance of explosion by not making the gunpowder. But if, beyond this safe and beneficial business, they ever try to explain anything to you, you may be confident of one of two things,—either that they know nothing (to speak of) about it, or that they have only seen one side of it—and not only haven't seen, but usually have no mind to see, the other. When, for instance, Professor Tyndall explains the twisted beds of the Jungfrau to you by intimating that the Matterhorn is growing flat;10 or the clouds on the lee side of the Matterhorn by the wind's rubbing against the windward side of it,11—you may be pretty sure the scientific people don't know much (to speak of) yet, either about rock-beds, or cloud-beds. And even if the explanation, so to call it, be sound on one side, windward or lee, you may, as I said, be nearly certain it won't do on the other. Take the very top and center of scientific interpretation by the greatest of its masters: Newton explained to you—or at least was once supposed to have explained—why an apple fell; but he never thought of explaining the exactly correlative, but infinitely more difficult question, how the apple got up there!
You will not, therefore, so please you, expect me to explain anything to you,—I have come solely and simply to put before you a few facts, which you can't see by candlelight, or in railroad tunnels, but which are making themselves now so very distinctly felt as well as seen, that you may perhaps have to roof, if not wall, half London afresh before we are many years older.
I go back to my point—the way in which clouds, as a matter of fact, become visible. I have defined the floating or sky cloud, and defined the falling, or earth cloud. But there's a sort of thing between the two, which needs a third definition: namely, Mist. In the 22d page of his 'Glaciers of the Alps,' Professor Tyndall says that "the marvelous blueness of the sky in the earlier part of the day indicated that the air was charged, almost to saturation, with transparent aqueous vapor." Well, in certain weather that is true. You all know the peculiar clearness which precedes rain,—when the distant hills are looking nigh. I take it on trust from the scientific people that there is then a quantity—almost to saturation—of aqueous vapor in the air, but it is aqueous vapor in a state which makes the air more transparent than it would be without it. What state of aqueous molecule is that, absolutely unreflective12 of light—perfectly transmissive of light, and showing at once the color of blue water and blue air on the distant hills?