THE CAMERA OBSCURA.

CAMERA OBSCURA is a machine or apparatus, by means of which, the images of external objects, transmitted through a convex lens, are distinctly exhibited in their natural colours, on a white tablet placed within the machine, and in the focus of the lens: in fact, it is

an ARTIFICIAL EYE.

Of all exhibitions, the Camera Obscura affords, to me, one of the most attractive. Only think of a PERFECT PICTURE! nature herself, painted by the radiant finger of light! And not only a PERFECT, but & LIVING picture! Absolute truth of form and colour, with MOTION superadded!

It is obvious, that much of the interest of this exhibition must depend upon the situation in which the machine is placed: and perhaps it would be difficult to select a more effective situation than the head of St. George's Pier at Liverpool: on which pier, while waiting with my family, one bright sunny morning, for the steam-boat which was to convey us to Rock-ferry, they and I were invited by a placard affixed to the door of a little wooden shed fitted up as a Camera Obscura, to pass the interval in gazing upon the optical wonders therein exhibited.

It would have been unreasonable to expect, that the lens and mirrors of this small, travelling machine should be adjusted with scientific accuracy: but any defects-and there was a want of distinctness in the images, and of vividness in the colouring-were compensated by the admirable position which the exhibitor had selected.

Steamers and sailing-boats passing and re-passing-the waves glittering in the sunshine, and rippling in the breeze-itinerant musicians, of whom several belonging to different nations and exhibiting various costumes, may generally be seen attending upon steam-boats -carriages from time to time, bringing passengers or luggage to the place of embarkation-and the multitude of persons of all grades who crowd the neighbourhood of the docks, some hurrying to and fro, in

tent upon their business, and others aroused for a few moments, from their habitual listlessness to watch the setting forth, or the returning of different vessels-all these form, together, a moving scene remarkable for its variety and interest, and possessing a character of cheerful activity, in the highest degree attractive.

Who, while gazing upon the images in a Camera Obscura, has not regretted, that these representations of nature, so clear, and bright, and full of life, are, at the same time, so volatile and evanescent? Who has not desired, that they could be rendered permanent? Such is the all but omnipotence of science, that even this desire is now, no longer extravagant. The simultaneous discoveries of Mr. Fox Talbot, and M. Daguerre established, some years since, the astonishing fact, that there exists a substance so sensitive of light, as to be capable of RETAINING its most faint impressions. This discovery is the foundation of the Photogenic art-the art of forming pictures or images of all natural objects, by means of solar light alone.

The self-painted pictures produced by this wonderful process, were,. indeed, at first, rather like Indian-ink drawings, than paintings: they had light and shade; but colour was wanting. Further experiments have, however, disclosed the means of supplying this want. It is, of course, essential to Photogenic painting, that the objects to be represented, should be at rest. In this respect, therefore, the Camera Obscura must always retain its superiority over the pictures produced by the new art.

While in the Camera Obscura on St. George's Pier, some of the younger members of my party, who could scarcely believe, that what they saw was an exact and real representation of what was actually passing outside the shed in which they were, desired their brother— by way of bringing the matter to the test-to go out and walk across the pier, and back again, and take off his hat, at a place agreed upon. He did so, and their delight on seeing him walk twice across the picture, and perform the appointed evolution, was such as I should find it difficult to describe. I have sometimes wondered, that in these days of luxury, when a new pleasure might be hailed as a rarity, that the possessors of the noble mansions with which our English counties abound, never fit up, in their beautiful grounds, some small ornamental structure, as a Camera Obscura. The thing might be easily done; and besides being an embellishment to the demesne in which it stood, and a source of much innocent and ever-varying amusement, such an edifice might answer some useful purposes. The Camera Obscurs

affords a good practical explanation of the nature of vision, and of the mode in which the images or pictures of external visible objects are formed upon the retina of the human eye and hence it has by some authors been called an artificial eye. Moreover, by the aid of certain very simple contrivances, a person quite unacquainted with the art of designing, may, by means of this instrument, delineate objects with great accuracy; and it is needless to add, that in the department of colouring, the lessons that a painter may learn from the Camera Obscura are beyond all price.

How wonderful, of late years, has been the progress of science! Dr. Darwin's prediction,

"Soon shall thy arm, unconquer'd steam! afar,
Drag the slow barge, or drive the rapid car:

Or on wide waving wings expanded, bear
The flying chariot through the fields of air,"

was probably, at the time when it was written, considered as a poetical extravagance; yet the first part of it has long been actually accomplished whether the second be yet fulfilled, it is, perhaps, amid the multitude of inventions perpetually announced to the public, difficult to pronounce; but we may safely venture to assert, that the idea of “THE FLYING CHARIOT" propelled by steam, is less extravagant now, than that of "THE RAPID CAR" must have appeared, when the above lines were written and the marvels daily effected by the lately discovered Photogenic art, had they been predicted in Dr. Darwin's time, would doubtless have been regarded as more extravagant than either. Some of the wonderful effects produced by the Camera Obscura, may be exhibited in any apartment, by the following simple means: close the shutters of any room whose windows afford a view of various objects; leaving only, in one shutter, one small circular aperture. Into this aperture fit a convex lens; and at a proper distance to be determined by experience-spread on a surface parallel to the shutter," a white paper or cloth. Upon this white surface the objects which reflect the rays of light which radiate through the aperture in the shutter, will be delineated. Unless, however, certain means, which need not here be described, be used, these objects will appear in an inverted position. If the aperture through which the light is admitted do not exceed the eighth of an inch in diameter, an image will be formed upon the opposite receiving surface, even though no lens be used.

In order to render the images thus produced, clear and distinct, it is necessary, that the aperture through which the rays from the objects to be delineated, are admitted, should be between those objects and the sun. Thus, if the aperture in the shutter have a western aspect, the phenomena to be exhibited will be best seen in the forenoon; ifan eastern, in the afternoon; if northern, about noon; a southern aspect, is, for obvious reasons, the worst; but even in that case, the desired effect will be produced, if care be taken that no light enter the apartment except through the aperture already mentioned, and that the light so admitted be not too powerful. It will, likewise, in this case, be advantageous, that the spectator, before entering the darkened chamber, should remain for a few minutes in absolute darkness. The greater the distance between the aperture and the white surface on which the rays are to fall, the larger will be the image; but its brightness will be diminished; and it will grow fainter and fainter in proportion to this distance, until, at length, it can no longer be discerned.

A Camera Obscura being thus easily constructed, some of its curious and beautiful phenomena may be readily exhibited. The means by which the images produced may be made to appear erect, instead of inverted, are very simple, and may be learned, with little difficulty, by any ingenious young person, from any Cyclopædia, or other work treating of practical optics. The effects produced will not, indeed, in ordinary situations, be so striking as those exhibited in the little shed on St. George's Pier; but if the simple apparatus be rightly adjusted, a picture will be exhibited which, in point of HARMONY OF COLOURING, will surpass any thing that can be imagined by a person who has never beheld a representation of nature, as painted by her own unerring hand, by means of the THE CAMERA OBSCURA.

MATERNAL RESPONSIBILITY.

T is difficult to find words which may adequately express the importance of the position in society maintained by MOTHers. A due sense of that importance, far from ministering to feelings of vanity, must bring

along with it a deep sense of the RESPONSIBILITY which is consequent upon the almost unlimited influence possessed by a mother over her children, and give rise to frequent and serious me. ditations on that solemn account, which she who is intrusted with this priceless talent, must render up, on the day when He who has said "occupy till I come," will demand an "account" of her "stewardship."

Let us briefly consider some of the grounds of a mother's responsibility.

She has the charge of IMMORTAL beings.

It is the IMMORTALITY of man, that gives importance to all human affairs. But for this, all would be vain indeed. Were it the destiny of men to flourish during their little day,-to weep, laugh, groan, die, and then perish for ever, then might we reasonably say to the mother, "make play-things of your children, and enjoy them; let your concern for them be limited to the care of the body, and the interests of this present life." Far different, however, is the truth. Behold that little one quietly hushed on its cradle pillow. Pleased with its little dreams, the unconscious smile now dimples its cheek; anon, its mental images assume a fearful shape; and its own frightened cry breaks its gentle slumbers. Awakened, it has no strength to raise its head; no language but its infant moans to indicate its wants. How frail is its form! how weak its hold on life! Touched by the rough hand of disease, it dies. What dies? Your babe? No; the cage is broken; but the bird is flown unhurt. YOUR INFANT LIves. All the vicissitudes of time, all the changes to which matter may be subjected, cannot destroy it. Immortality is its birthright. It will outlive the sun; survive the conflagration of unnumbered worlds ;