Chapter V: Sect. I.--On the Colours of Light (2)

_Lunar Rainbows._--A lunar bow is sometimes formed at night by the rays of the moon striking on a rain-cloud, especially when she is about the full. But such a phenomenon is very rare. Aristotle is said to have considered himself the first who had seen a lunar rainbow. For more than a hundred years prior to the middle of the last century, we find only two or three instances recorded in which such phenomena are described with accuracy. In the philosophical transactions for 1783, however, we have an account of three having been seen in one year, and all in the same place, but they are by no means common phenomena. I have had an opportunity within the last twenty years of witnessing two phenomena of this description--one of which was seen at Perth, on a sabbath evening, in the autumn of 1825, and the other at Edinburgh, on Wednesday, the 9th of September 1840, about eight o’clock in the evening--of both which I gave a detailed description in some of the public journals. The Moon, in both cases, was within a day or two of the full; the arches were seen in the northern quarter of the heavens, and extended nearly from east to west, the moon being not far from the southern meridian. The bows appeared distinct and well defined, but no distinct traces of the prismatic colours could be perceived on any of them. That which appeared in 1825 was the most distinctly formed, and continued visible for more than an hour. The other was much fainter, and lasted little more than half an hour, dark clouds having obscured the face of the moon. These bows bore a certain resemblance to some of the luminous arches which sometimes accompany the Aurora Borealis, and this latter phenomenon has not unfrequently been mistaken for a Lunar rainbow; but they may be always distinguished by attending to the phases and position of the moon. If the moon be not visible above the horizon, if she be in her first or last quarter, or if any observed phenomenon be not in a direction opposite to the moon, we may conclude with certainty that, whatever appearance is presented, there is no lunar rainbow.

The rainbow is an object which has engaged universal attention, and its beautiful colours and form have excited universal admiration. The poets have embellished their writings with many beautiful allusions to this splendid meteor; and the playful school-boy, while viewing the ‘bright enchantment,’ has frequently run ‘to catch the falling glory.’ When its arch rests on the opposite sides of a narrow valley, or on the summits of two adjacent mountains, its appearance is both beautiful and grand. In all probability, its figure first suggested the idea of _arches_, which are now found of so much utility in forming aqueducts and bridges, and for adorning the architecture of palaces and temples. It is scarcely possible seriously to contemplate this splendid phenomenon, without feeling admiration and gratitude towards that wise and beneficent Being, whose hands have bent it into so graceful and majestic a form, and decked it with all the pride of colours. “Look upon the rainbow,” says the son of Sirach,[15] and praise Him that made it: very beautiful it is in the brightness thereof. It compasseth the heaven about with a glorious circle, and the hands of the Most High have bended it." To this grand etherial bow, the inspired writers frequently allude as one of the emblems of the majesty and splendour of the Almighty. In the prophecies of Ezekiel, the throne of Deity is represented as adorned with a brightness “like the appearance of the bow that is in the cloud in the day of rain--the appearance of the likeness of the glory of Jehovah.” And, in the visions recorded in the Book of the Revelations, where the Most High is represented as sitting upon a throne; “there was a rainbow round about the throne, in sight like unto an emerald,” as an emblem of his propitious character and of his faithfulness and mercy. After the deluge, this bow was appointed as a sign and memorial of the covenant which God made with Noah and his sons, that a flood of waters should never again be permitted to deluge the earth and its inhabitants;--and as a pledge of inviolable fidelity and Divine benignity. When, therefore, we at any time behold “the bow in the cloud,” we have not only a beautiful and sublime phenomenon presented to the eye of sense, but also a memorial exhibited to the mental eye, assuring us, that, “While the earth remaineth, seed-time and harvest, and cold and heat, and summer and winter, and day and night, _shall not cease_.”[16]

----On the broad sky is seen
“A dewy cloud, and in the cloud a bow
Conspicuous, with seven listed colours gay
Betokening peace with God and covenant new.--
He gives a promise never to destroy
The earth again by flood, nor let the sea
Surpass his bounds, nor rain to drown the world.”
_Milton. Par. Lost, Book XI._

SECT. 4.--REFLECTIONS ON THE BEAUTY AND UTILITY OF COLOURS.

Colour is one of the properties of light which constitutes, chiefly, the beauty and sublimity of the universe. It is colour, in all its diversified shades, which presents to our view that almost infinite variety of aspect which appears on the scene of nature, which gives delight to the eye and the imagination, and which adds a fresh pleasure to every new landscape we behold. Every flower which decks our fields and gardens is compounded of different hues; every plain is covered with shrubs and trees of different degrees of verdure; and almost every mountain is clothed with herbs and grass of different shade from those which appear on the hills and landscape with which it is surrounded. In the country, during summer, nature is every day, and almost every hour, varying her appearance, by the multitude and variety of her hues and decorations, so that the eye wanders with pleasure over objects continually diversified, and extending as far as the sight can reach. In the flowers with which every landscape is adorned, what a lovely assemblage of colours, and what a wonderful art in the disposition of their shades! Here, a light pencil seems to have laid on the delicate tints; there, they are blended according to the nicest rules of art. Although green is the general colour which prevails over the scene of sublunary nature, yet it is diversified by a thousand different shades, so that every species of tree, shrub and herb, is clothed with its own peculiar verdure. The dark green of the forests is thus easily distinguished from the lighter shades of cornfields and the verdure of the lawns. The system of animated nature likewise, displays a diversified assemblage of beautiful colours. The plumage of birds, the brilliant feathers of the peacock, the ruby and emerald hues which adorn the little humming-bird, and the various embellishments of many species of the insect tribe, present to the eye, in every region of the globe, a scene of diversified beauty and embellishment. Nor is the mineral kingdom destitute of such embellishments. For some of the darkest and most unshapely stones and pebbles, when polished by the hand of art, display a mixture of the most delicate and variegated colours. All which beauties and varieties in the scene around us are entirely owing to that property, in every ray of light, by which it is capable of being separated into the primitive colours.

To the same cause, likewise, are to be ascribed those beautiful and diversified appearances, which frequently adorn the face of the sky,--the yellow, orange and ruby hues which embellish the firmament at the rising of the sun, and when he is about to descend below the western horizon; and those aerial landscapes, so frequently beheld in tropical climes, where rivers, castles and mountains, are depicted rolling over each other along the circle of the horizon. The clouds, especially in some countries, reflect almost every colour in nature. Sometimes they wear the modest blush of the rose; sometimes they appear like stripes of deep vermillion, and sometimes as large brilliant masses tinged with various hues; now they are white as ivory, and now as yellow as native gold. In some tropical countries, according to St. Pierre, the clouds roll themselves up into enormous masses as white as snow, and are piled upon each other, like the Cordeliers of Peru, and are moulded into the shape of mountains, of caverns and of rocks. When the sun sets behind this magnificent aërial net-work, a multitude of luminous rays are transmitted through each particular interstice, which produce such an effect, that the two sides of the lozenge illuminated by them, have the appearance of being begirt with a fillet of gold; and the other two which are in the shade, seem tinged with a superb ruddy orange. Four or five divergent streams of light, emanating from the setting sun up to the zenith, clothe with fringes of gold the undeterminate summits of this celestial barrier, and proceed to strike with the reflexes of their fires the pyramids of the collateral aerial mountains, which then appear to consist of silver and vermilion.--In short, colour diversifies every sublunary scene, whether on the earth or in the atmosphere, it imparts a beauty to the phenomena of falling stars, of luminous arches, and the coruscations of the Aurora Borealis, and gives a splendour and sublimity to the spacious vault of heaven.

Let us now consider for a moment, what would be the aspect of nature, if, instead of the beautiful variety of embellishments which now appear on every landscape, and on the concave of the sky,--_one_ uniform colour had been thrown over the scenery of the universe. Let us conceive the whole of terrestrial nature to be covered with snow, so that not an object on earth should appear with any other hue, and that the vast expanse of the firmament presented precisely the same uniform aspect. What would be the consequence? The light of the sun would be strongly reflected from all the objects within the bounds of our horizon, and would produce a lustre which would dazzle every eye. The day would acquire a greater _brightness_ than it now exhibits, and our eyes might, after some time, be enabled freely to expatiate over the surrounding landscape; but every thing, though enlightened, would appear _confused_, and particular objects would scarcely be distinguishable. A tree, a house or a church, near at hand, might possibly be distinguished, on account of its elevation above the general surface of the ground, and the bed of a river by reason of its being depressed below it. But we should be obliged rather to guess, and to form a conjecture as to the particular object we wished to distinguish, than to arrive at any certain conclusion respecting it; and if it lay at a considerable distance, it would be impossible, with any degree of probability, to discriminate any one object from another. Notwithstanding the universal brightness of the scene, the uniformity of colour thrown on every object, would most certainly prevent us from distinguishing a church from a palace, a cottage from a knoll or a heap of rubbish, a splendid mansion from rugged rocks, the trees from the hills on which they grow, or a barren desert from rich and fertile plains. In such a case, human beings would be confounded, and even friends and neighbours be at a loss to recognize one another.

The vault of heaven, too, would wear a uniform aspect. Neither planets nor comets would be visible to any eye, nor those millions of stars which now shine forth with so much brilliancy, and diversify the nocturnal sky. For, it is by the contrast produced by the deep azure of the heavens and the white radiance of the stars, that those bodies are rendered visible. Were they depicted on a pure white ground, they would not be distinguished from that ground, and would consequently be invisible, unless any of them occasionally assumed a different colour. Of course, all that beautiful variety of aspect which now appears on the face of sublunary nature--the rich verdure of the fields, the stately port of the forest, the rivers meandering through the valleys, the splendid hues that diversify and adorn our gardens and meadows, the gay colouring of the morning and evening clouds, and all that variety which distinguishes the different seasons, would entirely disappear. As every landscape would exhibit nearly the same aspect, there would be no inducement to the poet and the philosopher to visit distant countries to investigate the scenes of nature, and journeyings from one region to another would scarcely be productive of enjoyment. Were any other single colour to prevail, nearly the same results would ensue. Were a deep ruddy hue to be uniformly spread over the scene of creation, it would not only be offensive to the eye, but would likewise prevent all distinction of objects. Were a dark blue or a deep violet to prevail, it would produce a similar effect, and at the same time, present the scene of nature as covered with a dismal gloom. Even if creation were arrayed in a robe of _green_, which is a more pleasant colour to the eye--were it not diversified with the different shades it now exhibits, every object would be equally undistinguishable.

Such would have been the aspect of creation, and the inconveniences to which we should have been subjected, had the Creator afforded us light without that intermixture of colours which now appears over all nature, and which serves to discriminate one object from another. Even our very apartments would have been tame and insipid, incapable of the least degree of ornament, and the articles with which they are furnished, almost undistinguishable, so that in discriminating one object from another, we should have been as much indebted to the sense of touch as to the sense of vision. Our friends and fellow men would have presented no objects of interest in our daily associations. The sparkling eye, the benignant smile, the modest blush, the blended hues of white and vermillion in the human face, and the beauty of the female countenance, would all have vanished, and we should have appeared to one another as so many moving marble statues cast nearly in the same mould. But, what would have been worst of all, the numerous delays, uncertainties and perplexities to which we should have been subjected, had we been under the necessity, every moment, of distinguishing objects by trains of reasoning, and by circumstances of time, place, and relative position? An artist, when commencing his work in the morning, with a hundred tools of nearly the same size and shape around him, would have spent a considerable portion of his time before he could have selected those proper for his purpose, or the objects to which they were to be applied; and in every department of society, and in all our excursions from one place to another, similar difficulties and perplexities would have occurred. The one half of our time must thus have been employed in uncertain guesses, and perplexing reasonings, respecting the real nature and individuality of objects, rather than in a regular train of thinking and of employment; and after all our perplexities and conjectures, we must have remained in the utmost uncertainty, as to the thousands of scenes and objects, which are now obvious to us, through the instrumentality of colours, as soon as we open our eyes.

In short, without colour, we could have had no books nor writings: we could neither have corresponded with our friends by letters, nor have known any thing with certainty, of the events which happened in former ages. No written revelation of the will of God, and of his character, such as we now enjoy, could have been handed down to us from remote periods and generations. The discoveries of science, and the improvements of art, would have remained unrecorded. Universal ignorance would have prevailed throughout the world, and the human mind have remained in a state of demoralization and debasement. All these, and many other inconveniences and evils would have inevitably followed, had not God painted the rays of light with a diversity of colours, And hence we may learn, that the most important scenes and events in the universe, may depend upon the existence of a single principle in nature, and even upon the most minute circumstances, which we may be apt to overlook, in the arrangements of the material world.

In the existing state of things in the visible creation, we cannot but admire the Wisdom and Beneficence of the Deity, in thus enabling us to distinguish objects by so easy and expeditious a mode as _that of colour_, which in a moment, discriminates every object and its several relations. We rise in the morning to our respective employments, and our food, our drink, our tools, our books, and whatever is requisite for our comfort, are at once discriminated. Without the least hesitation or uncertainty, and without any perplexing process of reasoning, we can lay our hands on whatever articles we require. Colour clothes every object with its peculiar livery, and infallibly directs the hand in its movements, and the eye in its surveys and contemplations. But, this is not the only end which the Divine Being had in view, in impressing on the rays of light a diversity of colours. It is evident, that he likewise intended to minister to our _pleasures_, as well as to our wants. To every man of taste, and almost to every human being, the combination of colours in flowers, the delicate tints with which they are painted, the diversified shades of green with which the hills and dales, the mountains and the vales are arrayed; and that beautiful variety which appears in a bright summer day, on all the objects of this lower creation--are sources of the purest enjoyment and delight. It is colour, too, as well as magnitude, that adds to the _sublimity_ of objects. Were the canopy of heaven of one uniform hue, it would fail in producing those lofty conceptions, and those delightful and transporting emotions, which a contemplation of its august scenery is calculated to inspire. Colours are likewise of considerable utility in the intercourse of general society. They serve both for ornaments, and for distinguishing the different ranks and conditions of the community: they add to the beauty and gracefulness of our furniture and clothing. At a glance, they enable us at once to distinguish the noble from the ignoble, the prince from his subjects, the master from his servant, and the widow clothed with sable weeds from the bride adorned with her nuptial ornaments.

Since colours, then, are of so much value and importance, they may be reckoned as holding a rank among the noblest natural gifts of the Creator. As they are of such essential service to the inhabitants of our globe, there can be no doubt that they serve similar or analogous purposes throughout all the worlds in the universe. The colours displayed in the solar beams are common to all the globes which compose the planetary system, and must necessarily be reflected, in all their diversified hues, from objects on their surfaces. The light which radiates from the fixed stars displays a similar diversity of colours. Some of the double stars are found to emit light of different hues;--the larger star exhibiting light of a ruddy or orange hue, and the smaller one a radiance which approaches to blue or green. There is therefore reason to conclude, that the objects connected with the planets which revolve round such stars--being occasionally enlightened by suns of different hues--will display a more variegated and splendid scenery of colouring than is ever beheld in the world on which we dwell; and that one of the distinguishing characteristics of different worlds, in regard to their embellishments, may consist in the splendour and variety of colours with which the objects on their surfaces are adorned. In the metaphorical description of the glories of the New Jerusalem, recorded in the Book of Revelation, one of the chief characteristics of that city is said to consist in the splendour and diversity of hues with which it is adorned. It is represented as “coming down from heaven, _prepared as a bride adorned for her husband_,” and as reflecting all the beautiful and variegated colours which the finest gems on earth can exhibit; evidently indicating, that splendour and variety of colouring are some of the grandest features of celestial scenery.

On the whole, the subject of colours, when seriously considered, is calculated to excite us to the adoration of the goodness and intelligence of that Almighty Being whose wisdom planned all the arrangements of the universe, and to inspire us with gratitude for the numerous conveniences and pleasures we derive from those properties and laws he has impressed on the material system. He might have afforded us light, and even splendid illumination, without the pleasures and advantages which diversified colours now produce, and man and other animated beings might have existed in such a state. But, what a very different scene would the world have presented from what it now exhibits! Of how many thousands of pleasures should we have been deprived! and to what numerous inconveniences and perplexities should we have been subjected! The sublimity and glories of the firmament, and the endless beauties and varieties which now embellish our terrestrial system, would have been for ever unknown, and man could have had little or no incitement to study and investigate the works of his Creator. In this, as well as in many other arrangements in nature, we have a sensible proof of the presence and agency of that Almighty Intelligence “in whom we live, and move, and have our being.” None but an infinitely Wise and Beneficent Being, intimately present in all places, could thus so regularly create in us by means of colour, those exquisite sensations which afford so much delight, and which unite us, as it were, with every thing around us. In the diversity of hues spread over the face of creation, we have as real a display of the Divine presence as Moses enjoyed at the burning bush. The only difference is, that the one was out of the common order of Divine procedure, and the other in accordance with those permanent laws which regulate the economy of the universe. In every colour, then, which we contemplate, we have a sensible memorial of the presence of that Being “whose Spirit garnished the heavens and laid the foundations of the earth,” and whose “merciful visitation” sustains us every moment in existence. But the revelation of God to our senses, through the various objects of the material world, has become so familiar, that we are apt to forget the Author of all our enjoyments, even at the moment when we are investigating his works and participating of his benefits. “O that men would praise Jehovah for his goodness, and for his wonderful works towards the children of men.”