Abbildungen der Seite
PDF
EPUB

those laws, such a deviation may be reasonably expected. Were man, in the excrcise of his mental and corporeal powers, subjected to the laws of physical necessity, the circumstances supposed would indeed never occur, and of course no miracle could be admitted. But such is not the nature of man..

The relation between motives and actions is different from that between cause and efft ct in physics; and mankind have such command over themselves, as that by their voluntary conduct they can make themselves in a great degree either happy of miserable. We know likewise from history, that, by some means or other, almost all mankind were once sunk into the grossest ignorance of the most important truths; that they knew not the Being by whom they were created and supported; that they paid divine adoration to stocks, stones, and the vilest reptiles; and that they were slaves to the most impious, cruel, and degrading superstitions.

From this depraved state it was surely not unworthy of the common "Father of all" to rescue his helpless creatures, to enlighten their understandings that they might perceive what is right, and to present to them motives of sufficient force to engage them in the practice of it. But the understandings of ignorant barbarians cannot be enlightened by arguments; because of the force of such arguments as regard moral science they are not qualified to judge. The philosophers of Athens and Rome inculcated, indeed, many excellent moral precepts, and they sometimes ventured to expose the absurdities of the reigning superstition: but their lectures had no influence upon the multitude; and they had themselves imbibed such erroneous notions respecting the attributes of the Supreme Being, and the nature of the human soul, and converted those notions into first principles, of which they would not permit an examination, that even among them a thorough reformation was not to be expected from the powers of reasoning. It is likewise to be observed, that there are many truths of the utmost importance to mankind, which unassisted reason could never have discovered. Amongst these we may confidently reckon the immortality of the soul, the terms upon which God will be reconciled to sinners, and the manner in which that all perfect being may be acceptably worshipped; about all of which philosophers were in such uncertainty that, according to Plato, "Whatever is set right and as it should be, in the present evil state of the world, can be so only by the particular interposition of God."

An immediate revelation from Heaven, therefore, was the only method by which infinite wisdom and perfect goodness could reform a bewildered and vicious race. But this revelation, at whatever time we suppose it given, must have been made directly either to some chosen individuals commissioned to instruct others, or to every man and woman for whose benefit it was ultimately intended. Were every person instructed in the knowledge of his duty by immediate inspiration, and were the mot ves to practise it brought home to his mind by God himself, human nature would be wholly changed: men would not be masters of their own actions; they would not be moral agents, nor by consequence be capable either of reward or of punishment. It remains, therefore, that if God has been graciously pleased to enlighten and reform mankind, without destroying that moral nature which is essential to virtue, he can have done it only by revealing his truth to certain chosen instruments, who were the immediate instructors of

their contemporaries, and through them have been the instructors of succeeding ages.

let us suppose this to have been actually the case, and consider how those inspired teachers could communicate to others every truth which had been revealed to themselves. They might easily, if it were part of their duty, deliver a sublime system of natural and moral science, and establish it upon the common basis of experiment and demonstration; but what foundation could they lay for those truths which unassisted reason cannot discover, and which, when they are revealed, appear to have no necessary relation to any thing previously known? To a bare affirmation that they had been immediately received from God, no rational being could be expected to assent. The teachers might be men of known veracity, whose simple assertion would be admitted as sufficient evidence for any fact, in conformity with the laws of nature; but as every man has the evidence of his own consciousness and experience that revelations from heaven are deviations from these laws, an assertion so apparently extravagant would be rejected as false, unless supported by some better proof than the mere affirmation of the teacher. In this state of things, we can conceive no evidence sufficient to make such doctrines be received as the truths of God, but the power of working miracles committed to him who taught them. This would, indeed, be fully adequate to the purpose. For, if there were nothing in the doctrines themselves impious, immoral, or contrary to truths already known, the only thing which could render the teacher's assertion incredible, would be its implying such an intimate communion with God as is contrary to the established course of things, by which men are left to acquire all their knowledge by the exercise of their own faculties.-Let us now suppose some of those inspired teachers to tell his countrymen, that he did not desire them, on his ipse dixit, to believe that he had any preternatural communion with the Deity, but that for the truth of his assertion he would give them the evidence of their own senses; and after this declaration let us suppose him immediately to raise a person from the dead in their presence, merely by calling upon him to come out of his grave. Would not the only possible objection to the man's veracity be removed by this miracle? and his assertion that he had received such and such doctrines from God be as fully credited as if it related to the most common occurrence? Undoubtedly it would; for, when so much preternatural power was visibly communicated to this person, no one could have reason to question his having received an equal portion of preternatural knowledge palpable deviation from the known laws of nature, in one instance, is a sensible proof that such a deviation is possible in another; and in such a case as this it is the witness of God to the truth of

a man.

A

Miracles, then, under which we include prophecy, are the only direct evidence which can be given of divine inspiration. When a religion, or any religious truth, is to be revealed from heaven, they appear to be absolutely necessary to enforce its reception among men; and this is the only case in which we can suppose them necessary, or believe for a moment that they ever have been or will be performed.

The history of almost every religion abounds with relations of prodigics and wonders, and of the intercourse of men with the gods; but we know

of no religious system, those of the Jews and Christians excepted, which appealed to miracles as the sole evidence of its truth and divinity. The pretended miracles mentioned by Pagan historians and poets are not said to have been publicly wrought to enforce the truth of a new religion contrary to the reigning idolatry. Many of them may be clearly shown to have been mere natural events. Others are represented as having been per formed in secret on the most trivial occasions, and in obscure and fabulous ages long prior to the era of the writers by whom they are recorded. And such of them as at first view appear to be best attested, are evidently tricks contrived for interested purposes; to flatter power, or to promote the prevailing superstitions. For these reasons, as well as on account of the immoral character of the divinities by whom they are said to have been wrought, they are altogether unworthy of examination, and carry in the very nature of them the completest proofs of falsehood and imposture.

But the miracles recorded of Moses and of Christ bear a very different character. None of them is represented as wrought on trivial occasions. The writers who mention them were eyewitnesses of the facts; which they affirm to have been performed publicly, in attestation of the truth of their respective systems. They are indeed so incorporated with these systems, that the miracles cannot be separated from the doctrines; and if the mirades were not realy performed, the doctrines cannot possibly be true. Besides all this, they were wrought in support of revelations which opposed all the religious systems, superstitions, and prejudices, of the age in which they were given: a circumstance which of itself sets them, in point of authority, inAnitely above the Pagan prodigies, as well as the lying wonders of the Romish church.

It is indeed, we believe, universally admitted, that the miracles mentioned in the book of Exodus and in the four Gospels, might, to those who saw them performed, be sufficient evidence of the divine inspiration of Moses and of Christ; but to us it may be thought that they are no evidence whatever, as we must believe in the miracles themselves, if we believe in them at all, upon the bare authority of human testimony. Why, it has been sometimes asked, are not miracles wrought in all ages and countries? If the religion of Christ were to be of perpetual duration, every generation of men ought to have complete evidence of its truth and divinity.

To the performance of miracles in every age and in every country, perhaps the same objections lie as to the immediate inspiration of every individual. Were those miracles universally received as such, men would be so overwhelmed with the nature rather than with the force of their authority, as hardly to remain masters of their own conduct; and in that case the very end of all miracles would be defeated by their frequency. The truth, however, seems to be, that miracles so frequently repeared would not be received as such, and of course would have no authority; because it would be difficult, and in many cases impossible, to distinguish them from natural events. If they recurred regularly at certain intervals, we could not prove them to be deviations from the known laws of nature, because we should have the same experience for the one series of events as for the other; for the regular succession of preternatural effects, ás for the established constitution and course of things.

Be this, however, as it may, we shall take the liberty to affirm, that for the reality of the Gospel miracles we have evidence as convincing to the reflecting mind, though not so striking to vulgar apprehension, as those had who were contemporary with Christ and his apostles, and actually saw the mighty works which he performed. To the admirers of Mr. Hume's philosophy this assertion will appear an extravagant paradox; but we hope to demonstrate its truth from principles which, consistently with himself, that author could not have denied. He has indeed endeavoured to prove, that "no testimony is sufficient to establish a miracle;" and the reasoning employed for this purpose is, that "a miracle being a violation of the laws of nature, which a firm and unalterable experience has established, the proof against a miracle, from the very nature of the fact, is as entire as any argument from experience can be; whereas our experience of human veracity, which (according to him) is the sole foundation of the evidence of testimony, is far from being uniform, and can therefore never preponderate against that experience which admits of no exception." This boasted and plausible argument has with equat candour and acuteness been examined by Dr. Campbell; who justly observes, that so far is experience from being the sole foundation of the evidence of testimony, that, on the contrary, testimony is the sole foundation of by far the greater part of what Mr. Hume calls firm and unalterable experience; and that if in certain circumstances we did not give an implicit faith to testimony, our knowledge of events would be confined to those which had fallen under the immediate observation of our own senses. See ABRIDGEMENT.

But though Dr. Campbell has exposed the sophistry of his opponent's reasoning, and overturned the principles from which he reasons, we are persuaded that he might safely have joined issue with him upon those very principles. To us, at least, it appears that the testimony upon which we receive the Gospel miracles is precisely of that kind which Mr. Hume has acknowledged sufficient to establish even a miracle. "No testimony (says he) is sufficient to establish a miracle, unless the testimony be of such a kind that its falsehood would be more miraculous than the fact which it endeavours to establish. When one tells me that he saw a dead man restored to life, I immediately consider with myself whether it be more probable that this person should either deceive or be deceived, or that the fact which he relates should really have happened. I weigh the one miracle against the other and according to the superiority which I discover pronounce my decision, and always reject the greater miracle." In this passage every reader may remark, what did not escape the perspicacious eye of Dr. Campbell, a strange confusion of terms: but as all miracles are equally easy to the Almighty; and, as Mr. Hume has elsewhere observed, that "the raising of a feather, when the wind wants ever so little of a force requisite for that purpose, is as real a miracle as the raising of a house or a ship into the air;" candour obliges us to suppose, that by talking of greater and less miracles, and of always rejecting the greater, he meant nothing more, but that of two deviations from the known laws of nature he always rejects that which in itself is least probable.

If then we can shew that the testimony given by the apostles and other first preachers of Christianity to the miracles of their Master would, upon the

supposition that those miracles were not really performed, have been as great a deviation from the known laws of nature as the miracles themselves, the balance must be considered as evenly poised by opposite miracles; and whilst it continues so, the judgment must remain in a state of suspense. But if it shall appear, that in this case the false testimony would have been a deviation from the laws of nature less probable in itself than the miracles recorded in the Gospels, the balance will be instantly destroyed; and by Mr. Hume's maxim we shall be obliged to reject the supposition of falsehood in the testimony of the apostles, and admit the miracles of Christ to have been really performed.

In this argument we need not waste time in proving that those miracles, as they are represented in the writings of the New Testament, were of such a nature, and performed before so many witnesses, that no imposition could possibly be practised on the senses of those who affirm that they were present. From every page of the Gospels this is so evident, that the philosophical adversaries of the Christian faith never suppose the apostles to have been themselves deceived, but boldly accuse them of bearing false witness. But if this accusation be well founded, their testimony itself is as great a miracle as any which they record of themselves or of their Master.

Ideas and relations are in the mind of every man so closely associated with the words by which they are expressed in his native tongue, and in every other language of which he is master, that the one cannot be entirely separated from the other; and therefore no man can on any occasion speak falsehood without some effort; by no effort can a man give consistency to an unpremeditated detail of falsehood, if it be of any length, and include a number of particulars; and it is still less possible for several men to agree in such a detail, when at a distance from each other, and crossquestioned by their enemies.

This being the case, it follows, if the testimony of the apostles to their own and their Master's miracles be false, either that they must have concerted a consistent scheme of falsehood, and agreed to publish it at every hazard; or that God, or some powerful agent appointed by him, must have dissolved all the associations formed in their minds between ideas of sense and the words of language, and arbitrarily formed new associations, all in exact conformity to each other, but all in direct contradiction to truth. One or other of these events must have taken place; because, upon the supposition of falsehood, there is no other alternative. But such a dissolution and formation of associa. tions as the latter implies, must, to every man who shall attentively consider it, appear to be as real a miracle, and to require as great an exertion of power, as the resurrection of the dead. Nor is the supposed voluntary agreement of the apostles in a scheme of falsehood an event less miraculous. When they sat down to fabricate their pretended revelation, and to contrive a series of miracles to which they were unanimously to appeal for its truth, it is plain, since they proved successful in their daring enterprise, that they must have clearly foreseen every possible circumstance in which they could be placed, and have prepared consistent answers to every question that could be put to them by their most inveterate and most enlightened enemies; by the statesman, the lawyer, the philosopher, and the priest. That such foreknowledge as this would have been miraculous

will not surely be denied; since it forms the very attribute which we find it most difficult to allow even to God himself. It is not, however, the only miracle which this supposition would compel us to swallow. The very resolution of the apostles to propagate the belief of false miracles in support of such a religion as that which is taught in the New Testament, is as great a miracle as human imagination can easily conceive.

When they formed this design, either they must have hoped to succeed, or they must have foreseen that they should fail in their undertaking; and in either case, they chose evil for its own sake. They could not, if they foresaw that they should fail, look for any thing but that contempt, disgrace, and persecution, which were then the inevitable consequences of an unsuccessful endeavour to overthrow the established religion. Nor could their prospects be brighter upon the supposition of their success. As they knew themselves to be false witnesses and impious deceivers, they could have no hopes beyond the grave; and by determining to oppose all the religious systems, superstitions, and prejudices of the age in which they lived, they wilfully exposed themselves to inevitable misery in the present life, to insult and imprisonment, to stripes and death. Nor can it be said that they might look forward to power and affluence when they should, through sufferings, have converted their countrymen; for so desirous were they of obtaining nothing but misery as the end of their mission, that they made their own persecution a test of the truth of their doctrines. They introduced the Master, from whom they pretended to have received these doctrines, as telling them that "they were sent forth as sheep in the midst of wolves; that they should be delivered up to councils, and scourged in synagogues; that they should be hated of all men for his name's sake; that the brother should deliver up the brother to death, and the father the child; and that he who took not up his cross and followed after him was not worthy of him.” The very system of religion, therefore, which they invented and resolved to impose upon mankind, was so contrived, that the worldly prosperity of its first preachers, and even their exemption from persecution, was incompa tible with its success. Had these clear predictions of the Author of that religion, under whom the apostles acted only as ministers, not been verified, all mankind must have instantly perceived that their pretence to inspiration was false, and that Christianity was a scandalous and impudent imposture. All this the apostles could not but foresee when they formed their plan for deluding the world. Whence it follows, that when they resolved to support their pretended revelation by an appeal to forged miracles, they wilfully and with their eyes open exposed themselves to inevitable misery, whether they should succeed or fail in their enterprise; and that they concerted their measures so as not to admit of a possibility of recompense to themselves, either in this life or in that which is to come. But if there be a law of nature, for the reality of which we have better evidence than we have for others, it is, "that no maan can choose misery for its own sake," or make the acquisition of it the ultimate end of his pursuit. The existence of other laws of nature we know by testimony and our own observation of the regularity of their effects. The existence of this law is made known to us not only by these means, but also by the still clearer and more conclusive evidence of our own consciousness.

Thus, then, do miracles force themselves upon ear assent in every possible view which we can take of this interesting subject. If the testimony of the first preachers of Christianity was true, the miracles recorded in the Gospel were certainly performed, and the doctrines of our religion are derived from heaven. On the other hand, if that testimony was false, either God must have miraculously effaced from the minds of those by whom it was given all the associations formed between their sensible ideas and the words of language, or he must have endowed those men with the gift of prescience, and have impelled them to fabricate a pretended revelation for the purpose of deceiving the world, and involving themselves in certain and foreseen destruction.

བ་ ་

The power necessary to perform the one series of these miracles may, for any thing known to us, be as great as that which would be requisite for the performance of the other; and considered merely as exertions of preternatural power, they may seem to balance each other, and to hold the mind in a state of suspense. But when we take into consideration the different purposes for which these opposite and contending miracles were wrought, the balance is instantly destroyed. The miracles recorded in the Gospels, if real, were wrought in support of a revelation which, in the opinion of all by whom it is received, has brought to light many important truths which could not otherwise have been made known to men; and which, by the confession of its adversaries, contains the purest moral precepts by which the conduct of mankind was ever directed. The opposite series of miracles, if real, was performed to enable, and even to compel, a company of Jews, of the lowest rank and of the narrowest education, to fabricate, with the view of inevitable destruction to themselves, a consistent scheme of falsehood, and by an appeal to forged miracles to impose it upon the world as a revelation from heaven. The object of the former miracles is worthy of a God of infinite wisdom, goodness, and power. The object of the latter is absolutely inconsistent with wisdom and goodness, which are demonstrably attributes of that Being by whom alone miracles can be performed. Whence it follows, that the supposition of the apostles bearing false testimony to the miracles of their Master, implies a series of deviations from the laws of nature infinitely less probable in themselves than those miracles: and therefore, by Mr. Hume's maxim, we must necessarily reject the supposition of falsehood in the testimony, and admit the reality of the miracles. So true is it, that for the reality of the Gospelmiracles we have evidence as convincing to the reflecting mind, as those had who were contemporary with Christ and his apostles, and were actual witnesses to their mighty works.

As much of the discussion relative to miracles, according to the channel into which it has been thrown by Mr. Hume and his disciples, is made to turn upon the phrase "laws of nature;" we must not forget to remark that in this enquiry, nothing can consistently be meant by the laws of nature but those laws by which both the moral and physical worlds are governed; and that since this question respects altogether the moral government of God, the moral laws of nature ought here to fall principally under consideration. This consideration, however, is totally lost sight of, and the physical laws alone regarded by Mr. Hume in estimating the credibility of miracles; which is just as absurd as it would be to refer solely to the

laws of contracts, oaths, and premises, the cri-
teria of virtue and vice, and other moral princi-
ples, in order to investigate a correct and unob-
jectionable theory of physical astronomy.

Considered, then, in this point of view, it is
evident that the extraordinary nature of the fact is
no ground for disbelief, provided such a fact mo-
rally contemplated, was from the condition of
man become necessary; for in that case, the
Deity, by dispensing his assistance in proportioni
to our wants, acted upon the same principle as in
his more ordinary occupations. For whatever the
physical effects may be, if their moral tendency be
the same, they form a part of the same moral
law. Now in the events called miraculous, the
Deity is influenced by the same moral principle
as in his usual dispensations; and being induced
by the same motive to accomplish the same end,
the laws of God's moral government are not vio-
lated, such laws being established by the motives
and the ends produced, and not by the means em
ployed. In estimating, therefore, the credibility of
a miracle, we look at the moral not the physical
effect; and it is on this account that every un-
biassed mind is compelled almost antecedent to
any enquiry to reject most of the pretended mira-
cles of the Romish church. But estimating the
miracles of the apostolic age by this criterion, there
cannot be found the shadow of a reason for reject-,
ing them.

In this enquiry, too, it ought not to be forgotten that many of the first adversaries of our religion," and those the most formidable, never disputed the truth and reality of miracles; on the contrary, they mention them as having been performed. The Jews themselves acknowledged their reality. Julian and Celsus, two avowed enemies of Christianity, amongst all the arts which they used to destroy its credibility, ventured not to deny that our Saviour and his apostles wrought miracles; but ascribed them to magic. Facts confessed by those who had the greatest interest in denying them, ought to be admitted. But such is the hardihood of unbelief, such the impenetrability of the mind, when conviction must lead to an abandonment of practical as well as mental error, that our modern infidels deny what the first unbelievers with all their superior means of information found themselves obliged to admit. See farther the articles ABRIDGEMENT, CELSUS, CHRISTIA NITY, CREDIBILITY, JULIAN, PORPHYRY, &C.

MIRACULOUS. a. (miraculeux, French.) Done by miracle; produced by miracle; effected by power more than natural (Herbert). MIRACULOUSLY. ad. By miracle; by power above that of nature (Dryden).

MIRACULOUSNESS. s. (from miracu lous.) The state of being effected by miracle; superiority to natural power.

MIRADOR. s. (Spanish, from mirar, to look.) A balcony (Dryden).

MÍRANDA DO CORVO, a town of Por tugal, in Beira, 15 miles S. E. of Coimbra. Lon. 8. 10 W. Lat. 40. 2 N.

MIRANDA DE EBRO, a town of Old Castile, in Spain, 34 miles S. of Bilboa. Lat. 42. 49 N. Lon. 3. 10 W.

MIRANDE, a town of Gascony, in France. Lat. 43. 30 N. Lon. 0. 26 E.

MIRANDO DE DOURO, the capital of Tra los Montes, in Portugal. It is the see of a bishop, is well fortified, and is 37 miles

N.W. of Salamanca. Lat. 41. 40 N. Lon. 6.0 W.

MIRANDOLA, the capital of a duchy of the same nanie in Italy. It was taken by the king of Sardinia in 1742. It is 20 miles N.E. of Modena. Lat. 44. 52 N. Lon. 11. 19 E. MIRANDULA. See PICUS. MIRE. s. (moer, Dutch.) Mud; dirt at the bottom of water (Roscommon).

To MIRE. U. a. (from the noun.) To whelm in the mud; to soil with mud (Shakspeare). MIRE. S. (myna, Sax. mier, Dutch.) An ant; a pismire.

MIRINESS. s. (from miry.) Dirtiness; fulness of mire.

MIRKSOME, a. Dark ; obscure (Spenser). MIRROUR, in catoptrics, any polished body impervious to the rays of light, and which reflects them equally.

Mirrours were anciently made of metal; but, at present, they are generally smooth plates of glass, tinned or quicksilvered on the back part, and called looking-glasses. The doctrine of mirrours depends wholly on that fundamental law, that the angle of reflection is always equal to the angle of incidence. See OPTICS.

Parallel rays falling directly on a plane speculum are reflected back upon themselves; if they fall obliquely, they are reflected in the same angle, and parallel as they fell. Hence there is no such thing, properly speaking, as a focus belonging to a plane speculum, neither real nor virtual. The focus of parallel rays is called the solar focus; because in that the image of the sun is formed, and of all objects very remote. But the focus of any object situated near the mirrour, will have its distance from the vertex more or less than half the radius; the rule in all cases being as follows: Multiply the distance of the object into the radius of the mirrour, and divide the product by the sum of the radius, and twice the distance of the object; the quotient will be the focal distance of a convex mirrour."

Again, for a concave mirrour, the same product of the radius into the distance of the object, divided by the difference of radius and twice the distance of the object, will give the focal distance. And here we are to observe, that, as twice the distance of the object is lesser or greater than the radius, so the focus will be positive or negative, that is, behind the glass or before it.

The image of the object is formed in the focus proper to its distance, and, since the writers on optics demonstrate that the angles under which the object and its image are seen from the centre or vertex of the mirrour are always equal, it follows, that the image will be always in proportion to the object, as the focal distance to the object's distance. The position of the object will be always erect at a positive focus, or behind the speculum diminished by a convex, and magnified by a concave one. Hence, since a convex has but one, viz, an affirmative focus; so it can never magnify any object, howsoever posited before it.

The position of the image in a negative focus, or that before the glass, will be ever inverted; and, if nearer the vertex than the centre, it will be less; if further from it, it will be greater than the object; but in the centre it will be equal to the object, and seen to touch it.

The image formed by a plane speculum is erect, large as the life, at the same apparent distance behind the glass as the object is before it, and on the same side of the glass with the object. Those properties render this sort of mirrour of most common use, viz. as a looking-glass.

If the rays fall directly, or nearly so, on a plane mirrour, and the object be opaque, there will be but one single image formed, or at least be visible, and that by the second surface of the speculum, and not by the first, through which the rays do most of them pass.

But if the object be luminous, and the rays fall very obliquely on the speculum, there will be more than one image formed to an eye placed in a proper position to view them. The first image being formed by the fist surface, will not be so bright as the second, which is formed by the second surface. The third, fourth, &c. images are produced by several reflections of the rays between the two surfaces of the speculum; and, since some light is lost by each reflection, the images from the second will appear still more faint and obscure to the eighth, ninth, or tenth, which can scarcely be discerned at all.

Mirrours may be divided into plane, concave, convex, cylindrical, conical, parabolical, and elliptical.

The properties of cylindrical mirrours are, 1. The dimensions of objects corresponding lengthwise to the mirrour are not much changed; but those corresponding breadthwise have their figures altered, and their dimensions lessened the further from the mirrour; whence arises a very great distortion. 2. If the plane of the reflection cut the cylindric mirrour through the axis, the reflection is performed in the same manner as in a plane mirrour; and if parallel to the base, the reflection is the same as in a spherical mirrour; if it cut it obliquely, the reflection is the same as in an elliptic mirrour. Hence, as the plane of reflection never passes through the axis of the mirrour, except when the eye and objective line are in the same plane; nor parallel to the base, except when the radiant point and the eye are at the same height; the reflection is therefore usually the same as in an elliptic one. 3. If a hollow cylindric mirrour be directly opposed to the sun, instead of a focus of a point, the rays will be reflected into a lucid line parallel to its axis, at á distance somewhat less than a fourth of its diameter. Hence arises a method of drawing anamorphoses, that is, wild deformed figures on a plane, which appear well proportioned when viewed in a cylindric mirrour.

In an elliptic mirrour, if a ray strike on it from one of its focuses, it is reflected into the

« ZurückWeiter »