No XIV.

VOL. III.

DESCRIPTION OF THE PATENT KALEIDOSCOPE, INVENTED BY DR BREWSTER.

THE Kaleidoscope is an instrument recently invented by Dr Brewster, for the purpose of creating and exhibiting an infinite variety of beautiful forms. The name is derived from the Greek words, xaλos, beautiful—udos, a formand now, to see.

This instrument, in its simplest form, consists of two reflecting planes, made either of new plate glass or speculum metal, ground perfectly flat, and highly polished. The plates may be of any length, but that which is most convenient will be found to be from 5 to 10, or 12 inches. Their breadth should be about 8 or 9 tenths of an inch when the length is 6 inches, but the breadth should increase with the length, in order to have the aperture of the same angular magnitude. Two of the edges of these reflectors, after they are carefully ground to a straight line by the finest emery, and freed from all roughness and imperfection, are placed together, by a particular contrivance, in such a manner, that their inclination, or the angle which they form, is exactly an even aliquot part of a circle, or a 4th, 6th, 8th, 10th, 12th, 14th, 16th, 18th, 20th, &c. part of 360°. When the plates are thus fixed in a brass tube, and the eye placed at one end of them, it will perceive a circular field of view, composed of as many luminous sectors as the number of times that the angle formed by the reflectors is contained in 360°. These sectors, excepting the one seen by direct vision, and constituting the angular aperture of the plates, are a series of images of this aperture, formed by successive reflexions between VOL. III.

the inclined reflectors. The images formed by one reflexion from each of the plates, lie on each side of the direct aperture, and are inverted images of that aperture; the next two images, formed by two reflections, are images not inverted, and so on throughout the whole series, every two direct images being separated by an inverted one.

From these observations it will be seen, that the Kaleidoscope is not an instrument which produces beautiful forms by the multiplication of single forms; for it is demonstrable, that a symmetrical and beautiful pattern cannot be produced by the repetition of any single form; and if it were possible to construct a multiplying glass with mathematical perfection, and free of all the prismatic colours, it would be impossible to produce with it an arrangement of simple forms, marked with symmetry and beauty. The principle of the Kaleidoscope therefore is, to produce symmetry and beauty by the creation and subsequent multiplication of compound forms, each of which is composed of a direct and an inverted image of a simple form.

The tube which holds the reflecting plates moves in another tube, and upon the outer end of this last tube is placed a brass cell, or cap, for receiving a series of object-plates, containing fragments of differently coloured glass, and other substances, placed at random. When one of these object-plates is pushed into the cell, the cell is placed upon the end of the outer tube, and the inner tube pushed in as far as it will go. The instrument being held in one hand, the cell containing the objectplate is moved round by the other; and the eye of the observer being placed at the narrow end of the tube, he will Q

observe the irregular masses of colour arranged in an infinite variety of forms, mathematically symmetrical, and highly pleasing to the eye.

"If the object is put in motion, the combination of images will likewise be put in motion, and new forms perfectly different, but equally symmetrical,-will successively present themselves, sometimes vanishing in the centre, sometimes emerging from it, and sometimes playing around it in double and opposite oscillations. When the object is tinged with different colours, the most beautiful tints are developed in succession, and the whole figure delights the eye by the perfection of its form, and the brilliancy of its colouring.'

The effects, of which we have given a general description, obviously arise from the inversion and subsequent multiplication of every object placed before the angular aperture, or the luminous sector seen by direct vision, and from the perfect junction of all the reflected images. When the object is moved, the inverted images all seem to move in an opposite direction, while the images not inverted move in the same direction with the object; and from these opposite motions, as well as from the entrance of new objects, by the revolution or the direct motion of the object-plate, arises that endless variety of forms which affords so much gratification to the eye.

In the preceding form of this instrument, the object must necessarily be placed close to the end of the reflectors; for if it is removed from this position, the symmetry is destroyed, and the deviation from a symmetrical form increases as the distance of the object from the reflector increases. The use of the instrument is therefore limited to objects which can be held close to the reflector.

This limitation, however, has been removed, and the use and application of the instrument indefinitely extended by an optical contrivance. A lens of a short focal length is placed on the object end of the outer tube, and the inner tube is drawn out till the image of objects, whatever be their distance, falls exactly on the outer ends of the reflectors. When this is the case, these objects will be arranged into the most

* Specification of the Patent.

beautiful and symmetrical forms, in the same manner as if they had been reduced in size, and actually placed at the end of the reflectors. In this way every object in nature may be introduced into the picture formed by the instrument, and the observer will derive a new and endless source of enjoyment by the creation of pictures from natural objects, whether animate or inanimate. The leaves and petals of flowers, the foliage of trees, grass mixed with flowers, the currents of a river, moving insects, a blazing fire, are objects which never fail to delight the eye by the new creations which they afford.

The Kaleidoscope, in its popular form, has been manufactured with much taste by Mr Philip Carpenter, optician in Birmingham, and by Mr John Ruthven of Edinburgh, to whom the public is already indebted for the ingenious printing and copying presses with which he has enriched the arts. It generally consists of two tubes, a lens, six object-plates, one of which is left empty for new objects, and a cell for containing them. Some of them are made without the drawer tube and the lens, and others with stands, and a spare tube which forms a different pattern.

When the Kaleidoscope is intended for scientific purposes, it requires to be made in a different form, with contrivances for varying the inclination of the reflectors. The instrument, with these contrivances, has been made with great skill by Mr Bate, an ingenious optician in London. The reflectors are made of the finest speculum metal, of such a composition that it is incapable of tarnishing. The edges of these metallic reflectors are adjusted with great nicety to the axes of the rings that support them, so that they are made to form any angle from 0° to 90°.

As the Kaleidoscope is of the greatest use in the ornamental arts, particularly to carpet and lace manufacturers, calico printers, architects, paper stainers, ornamental painters, jewellers, carvers and gilders, workers in stained glass, &c. its adaptation to their purposes has been attended to, and the instruments are occasionally furnished with a stand, in order that the pattern may be fixed whilst the artist is engaged in copying it. They are also rendered capable of being used with

Dr Wollaston's Camera Lucida, in order that those who are not able to copy the patterns with perfect correctness, may thus be enabled to do it with facility and accuracy.

When the instrument is thus constructed, the painter may introduce the very colours which he is to use, the jeweller the gems which he is to arrange, and in general the artist may apply to the instrument the materials which he is to embody, and thus form the most accurate opinion of their effect when combined into an ornamental pattern. When the Kaleidoscope is applied in this manner, an infinite variety of patterns is created, and the artist can select such as he considers most beautiful and most suited to the nature of his work. After a knowledge of the principle and powers of the instrument has been acquired by a little practice, he will be able to give any character to the figure that he pleases, and he may even create a series of different patterns, all rising out of one another, and returning again, by similar gradations, to the first of the series. In all these cases the pattern is perfectly symmetrical round a centre, or all the sectors, or images of the aperture, are exactly alike, with this difference only, that every alternate sector is inverted; but this symmetry may be altered, for after the pattern is drawn, it may be reduced into a square, a triangular, an elliptical, or any other form that we choose. The instruments are sometimes made to give annular patterns, and straight patterns for borders.

If it is required to introduce a flower, a leaf, a statue, or any other object which is too large to be seen through the aperture, we have only to use the lens, and place the object at such a distance that the image of it, formed by the lens, is sufficiently small to be admitted into the aperture.

In consequence of the popularity of this instrument, it has, we under stand, been pirated in London by individuals who are entirely ignorant of its principles and construction, and who have imposed upon the public a wretched imitation of the original, possessing none of the properties which are essentially necessary to the production of beautiful and symmetrical forms. These piracies have been carried on with such dexterity, that in some cases the purchaser obtains one

half of the instrument in one shop, and the other half in another; but this unprecedented invasion of private property has been discountenanced by all the eminent London opticians with a liberality and disinterestedness which might have been expected from that respectable body; and we have no doubt that the public will be equally disposed to discourage such unjustifiable aggressions. Monopolies are no doubt in many cases evils that ought to be avoided; but in this country, a patent is the only reward which is given for mechanical inventions, and for new processes in the arts; and we do not see why the inventor of a machine should not derive the same advantages from his labours that every author does from his writings.

Those who wish for further information respecting the Kaleidoscope, may consult the printed description of it which accompanies the patent instrument, an ingenious paper on the Kaleidoscope in Thomson's Annals of Philosophy, vol. XI. written by Peter Roget, M.D. F.R.S., and a Treatise on the Principles of the Kaleidoscope, and its Application to the numerous branches of the fine and useful Arts, which will soon be published by Dr Brewster.

ON TRUTH.

The Reverie of an Enthusiast.

THE purposes of life are so various, and its powers so limited, that the mind can scarcely reflect upon its state, without discerning at once a vast inadequacy of the existence it carries on, to the requisitions under which that existence is held, and without feeling a nothingness in that present instant in which the form of its existence is brought, as in a concentrated image, before its inspection. What follows? Either the mind gathers up all the consciousness of its strength and of its destination, and, with violent commotion of its powers, believes and wills a greater future,-or it submits itself patiently to the seeming constitution of a frail nature, contented to know that it shall go on hereafter as it has gone on hitherto :-And so life passes. And is this all? Is this plausible humility of self-knowledge, which suits

so happily the indolent virtue of the world, and squares so well with the unaspiring prudence of its wisdom, is this Truth? And is that sudden, violent, momentary, grasping of a prouder spirit-is that illusion-the fond folly of presumptuous self-ig

norance,

"That raught at mountains with outstretched arms,

And parted but the shadow with his hand?" Who shall give the answer? The same division of spirit among men, which has divided their conduct, divides also their understanding, and each will answer from his own spirit, as it may have been enlightened, or corrupted, or bewildered, by his past life, and not from inquisition of truth. Though perhaps no man ever feels with full conviction that he possesses truth, yet every man, except in his despairing moments, assures himself that he is near to it, and perhaps he is so,— as if there were but a veil interposed that he cannot put aside, which sometimes gathers in thicker folds under his hand, and sometimes, perhaps without his endeavour, parts for a moment, and then closes again, while he is yet gazing.

Those who have upheld, as philosophical dogmas, asseverations of our utter incapacity for truth, and have, for their system of nature, represented man as a being bewildering himself, hopelessly and in vain, in dark and inextricable mazes of thought,-have spoken falsely to their own minds, and falsely to the convictions of men. There is no such belief in the human mind: no man, looking back upon his own life, whatever seasons of gloom he may have known, can find a fixed habitual consciousness of living on in bewildering darkness. That forlorn estate is not known to our natural life: There is no place then for such philosophy in nature. But there have been men, who, living according to their own belief, in the very light of their minds, have chosen in their pride, or been otherwise misled, to cast such disheartening illusions on the belief of others, and have given a show of truth to a false philosophy, by taking out from the whole course of life its unhappiest moments, and constituting into a system of permanent belief, the naturally transient impressions of fear, sadness, suspicion, self-aversion, and despair.

We all feel that there is a light by which we must regulate our lives. This is the common consenting belief of all mankind. No doubt their conceptions of truth are various. The impulse, the instinct of nature, which urges them, is the same to all. But soon variance begins by the diversity of individual being. Each sees by his own light, and amidst his own illusions. Each views in different aspect the mysterious, half-revealed, uncomprehended power, which is ever present and ever remote: he shapes by his own mind that undefined form. As his heart suggests-as his will purposes-as his thought dares-he hopes, demands, conceives truth. This he does, not in order to submit himself to truth, but to subject truth to himself, to incorporate her power with his own life. Truth, by which he may strengthen, exalt, enlarge his own being, is what he seeks; not truth, therefore, awful, authoritative, and controlling, but truth fettered and ministering; truth justifying himself to himselfsoothing his pride-licensing his passions-taking her looks, her life, her law, her being, from himself. Each man seeks truth, but each his own. And hence is there such diversity in all the opinions of men. Hence is it that, from the birth of science to this hour, philosophy has so often changed her shape,-that the labour of one age has been to pull down the fabric of another, and to build as perishably upon its ruins. Hence is it that the same original principle of belief and desire, working in the minds of fellow-men, has so often conducted them, not to common participation in common good, but to fearful division and implacable hate-to dissensions of opinion-convulsing life,-when the vulgar passions of men have stood aloof and astonished, to see speculative intellect kindle the torch, and forge the sword, to arm the bands of common

war.

Each man believes that he desires and seeks truth, that in part he knows it, and in part subjects the course of his life to that knowledge. But when he bends his mind thitherward, he brings it, such as it is, unpurified, unchastised, full of illusions of its own cherishing. Is it wonderful then, if men, thus making endeavour, find no better success? if, under incitement of a principle which might guide them