clock directly overhead. this city. The reason that so large an instrument is demanded-for this is the largest reflector in use in America-is, that a great amount of light must be collected to get a photograph of such a size that it will bear magnifying, and yet can be taken quickly. The problem is just the same as in portrait photog Now Europe, Asia, and Africa would be visible; in a few hours they would set, and North and South America, in their turn, come into view. They would have no need of watches. Our large cities would be visible through a telescope, a spot 500 feet square being distinctly perceptible. But it is of no use to speculate on the appear-raphy—the larger the lens the more quickly can ance of things that are not seen. a picture of a given size be taken. It was ignorance of this fact that led Daguerre, who invented the daguerreotype process, to declare that human portraits could not be taken photo So far from perceiving any visible traces of human habitation on the Moon through our telescopes, she presents to the eye only a desolate sterile waste. There are no tokens of activ-graphically. According to his ideas, and with ity. Even her volcanoes are extinct. We are his apparatus, it was necessary to sit more than able to determine now with precision their un- two hours, and that requires more patience or changed condition by the aid of photographs stolidity than most of us have. My father, taken from time to time. They show no change however, overturned this idea, and in 1839 sucthough an interval of years may have elapsed. ceeded in the University of this city in getting It is true, nevertheless, that minute changes the first portrait from life. One of the earliest may be occurring, for the difficulties of obtain-is still in existence in the possession of Sir ing first-class photographs are so great that John Herschel, who states that it is as good as slight eruptions might be overlooked.* I when first made. In the enlarged photographic view which you are going to see upon the screen there are many points to which your attention might be directed. Of these we shall select only a few, as a full ex The taking of a photograph of the Moon may be compared to getting the likeness of a man who is rapidly walking. We can not fasten her with a clamp as they do one's head at a photographer's establishment, it is necessary to neu-planation of all would demand too much time.* tralize the motion by another precisely similar. You will perceive, in the first place, that the This fortunately we can accomplish by fine whole circular face of the Moon is not presentclock-work so contrived as to make the telescope ed to you; only one semicircle is visible. The by which the photograph is taken point stead-photograph is taken from the Moon in her third ily at the same part. But there is another mo- quarter, when she was 21 days old, because at tion we can not neutralize, arising from the that time it better exhibits the more striking tremors of our air. Any one who has looked peculiarities than when full. You will remark across the top of a hot stove at objects beyond that the semicircle is diversified with light and will have perceived that their outlines are con- shadow: some parts are dark and others light. fused, and that they seem to tremble or vibrate The interpretation that is put on this variation rapidly. Precisely such movements are taking is, that the Moon, like the Earth, is composed place in the air above us, and these cause the of rocks of many different tints; that the large mountains on the moon to twinkle like a star. spaces I now indicate, and which used to be During two years, in which I took photographs | called seas, are made up of a darker rock than of the Moon every night that she shone, only the volcanic southern regions. At the tip of three good nights occurred, and even on these the rod, the volcano Copernicus has ejected a there was some vibrating motion. Professor lava whiter than the plains over which it has Bond, of the Cambridge Observatory, said that flowed. Observe how far the stream running he had never in his lifetime seen a perfectly north has gone; let me give you a scale of faultless night. If, then, it were desired to con- miles: this picture is 12 feet in diameter; it vey to you by our former simile of a man walk-shows the Moon as she would appear to us if ing the difficulties of Moon photography, it would be necessary to superadd that the man was afflicted with St. Vitus's dance. Besides all these obstacles others must be specified. A telescope of very large size is necessary in order that photographs may be procured with rapidity, and such an instrument is difficult to obtain. It must be either bought or made by the observer. In the latter case the time consumed in perfecting the lenses or mirrors is very great. I spent six years on my instrument, but had then the satisfaction of knowing that it was thoroughly adapted to its purpose. It has a mirror 15 inches in diameter, and a tube 12 feet long, and is mounted at Hastings on Hudson, 20 miles north of A fac-simile of Dr. Draper's photograph of the Moon was published in Harper's Weekly for March 19, 1864. we were 166 miles from her, instead of 240,000, as we now are. Every foot length in the picture is about 180 miles. You will see that the lava stream running north has gone not less than 600 or 800 miles. I have said that this lava is running across a plain. Why do we not call it by the old name, a sea-the Sea of Showers? If you will look closely and reason a little, the cause will be apparent enough. If this dark spot were a sheet of water it would present a uniform grayish or greenish tint. But we see it diversified with mottlings of light and shade, bright points and streaks of white lava. It must be land. * Here was exhibited an enlarged view of a photograph of the Moou. The picture was about 12 feet in diameter; the light and shade, craters, mountains, etc., were shown beautifully defined. points are seen apparently altogether disconnected from her. These are the tips of mountains, or the rims of craters, on which the sun In the next place, we will examine the straight or rugged side of the picture. On casting the eye along this part it will at once be noticed that it is irregular and seems to be thickly dot-light is falling while it does not reach their ted with depressions of a saucer shape. It is sometimes said that the Moon looks as if she had suffered from an attack of small-pox. What is the nature of these marks? bases. On the Earth the Sun in rising illuminates first the peaks of mountains, and then the light gradually creeps down their sides until they are all lightened up. So it is in the Moon. If the photograph had been taken a little while later than it was many of these bright points on the edge would have disap Let me observe that there are not on the Moon a large number of mountains, truly speaking-that is, ranges of projecting peaks. The best example of them is this range, the "Lu-peared, because this is a photograph of the nar Apennines;" they are perhaps 400 miles long at this part, and 15,000 feet high. waning Moon; they were depicted just as the Sun was setting on them. You may ask how we know that one spot is Why is it that the parts on the left hand of a mountain, another a crater. It is by observ- the picture are of so uniform a brightness, and ing the direction in which the shadows are cast. do not show craters and peaks too? It is beThe Moon does not shine by her own light, cause the light is there falling perpendicularly but is seen by light falling on her from the on the surface and illuminating all parts uniSun and reflected to us. The Earth is just as formly. If a person were suspended in a balbright to her as she is to us. When the Moon loon over the Earth, and the Sun were overis at half, as she is represented in this photo-head, he would find difficulty in distinguishing graph, the light falls obliquely on the part we a mountain from the valleys around if similarhave called the rugged edge, just as at sunrise ly composed. But in the morning, when the on the Earth. Every object that projects is Sun's rays strike the surface obliquely and the bright on the side toward the light, and in mountains cast a shadow, there would be no shadow on the opposite side, while every exca-difficulty. The part of the Moon on the exvation or pit is in just the reverse condition-treme left is here seen at mid-day, so to speak, bright on the side from the Sun, and dark on that at the rugged edge at evening.* the side toward him. Bearing this in mind, let us investigate some of these spots in the Moon. The Sun is away toward the left hand; in the Apennines the bright side is toward the left, and the dark toward the right. They are therefore, according to our rule, projections. But in this crater the dark side is toward the left, and the bright toward the right. It must be a pit. In this crater, named after Aristillus, you will observe a peculiarity common to many of the craters. It has in the centre a small bright dot, resulting from light falling on a conical mountain. This same central cone is seen in certain volcanic mountains on the Earth, as in Vesuvius for example. Any one who has ascended it will remember that the cone which now emits lava occasionally is surrounded at a distance by an old crater, just as if in the centre of a saucer a small pile of sand should be placed; the latter would represent the cone, while the rim of the saucer would be the wall of the crater. Here I point out another named after Eratosthenes; here another, etc. And now what is to be said on the subject of Plurality of Worlds is about finished. We have taken a glance at the celestial bodies, and shown that on one of them, a near neighbor, Mars, the conditions exist necessary to ani|mated beings. From it we may extend the observation to some of the rest. I could not offer you positive proofs, but have indicated how strong the probabilities are of inhabitation. In all such investigations it is necessary to be very careful in drawing conclusions from what we may see. The senses alone often deceive us, and results derived from them must be corroborated by our reason. Many instances could be adduced in proof of this assertion, and none more striking than those in connection with the body whose description has occupied so much of this evening. It is generally supposed that the rays proceeding from the Moon are so cold as to produce refrigeration in bodies exposed to them. This property has been a favorite subject of comparison with poets, as a thousand quotations concerning her cold, pale light would prove. In the old mythology the lack of warmth of Diana was typified by this body. But what In the In the cut on page 46 a part of the rugged edge of the Moon is shown. The drawing is from Professor Nichol's Cyclopedia. The reader will observe the long shadows cast by the mountain peaks and edges of craters. other cut, page 47, which is from a drawing by the eminent engineer James Nasmyth, a more full illumination of the surface is exhibited. It gives an admirable idea of the broken, volcanic nature of the surface of our satellite, and The various craters in the Moon have been named after distinguished men; this one, for instance, is Copernicus, who revived the doctrine that the Sun is the centre of the Solar System; this after Kepler, the discoverer of three great astronomical laws; this after Tycho Brahe, the Dane; this after Plato, etc. The dark parts are named from imaginary qualities they were supposed to possess; this is the Sea of Showers, or Mare Imbrium; this the Oce-suggests at once the sterility and uninhabitability of such anus Procellarum, or Ocean of Storms; this a place. But excellent as these drawings are they can convey but a faint idea of the beauty of the Moon as a telethe Sea of Vapors. scopic object. The photograph, enlarged by the calcium Along the extreme edge of the Moon many light, has more nearly the general effect. are the facts in the case? The Moon reflects to us a certain proportion of heat from the Sun, and by thermometers sufficiently delicate the amount may be measured. An ordinary mercurial thermometer fails entirely to show any rise, though the moonbeams be concentrated by ever so large a lens. But if two wires, one of bismuth and the other of antimony, be soldered together at the ends, an exceedingly slight warming at the junction will cause an electrical current to be developed. By appropriate contrivances we are able to measure the strength of the current, and as it bears a relation to the amount of heat employed, thus measure that heat. A number of pairs of such metals soldered together is called a thermoelectric pile. By the thermo-electric pile of a degree may be indicated. The moonbeams warm us to about this extent. To be sure the amount is not great, but it is sufficient to overturn the idea of her cooling agency. In another instance a deception of the eye is shown. When the moon is rising it is generally conceded that she is much larger than when near the zenith. She seems as large as a cart-wheel, while overhead the diameter is not greater than a plate. Any one who doubts this doubts the evidence of the senses. And yet measured with the telescope the size is seen to be the same on each occasion. Does not such a fact shake our confidence in the eye? A still more common deception which astronomers have to combat is that connected with the apparent size of the Moon. When it was stated a moment ago that overhead she seems as large as a plate, no dissent was expressed, because almost every one feels convinced that such is the fact from repeated observation. But yet by two simple experiments our faith in that can be altogether broken. Many times the inquiry is made in my observatory, "How large do you take your photographs of the Moon in the telescope?" On returning the answer that they are magnified 15 times by the instrument, and then showing a specimen about an inch and a half in diameter, persons either say, "This is smaller than the Moon," or else express their disbelief in a yet more marked manner by a silent dissent. The size of the Moon as seen by the naked eye is about that of a pepper-corn. Now that I know this to be the case she has lost her former magnitude to my eyes. In order to convince persons it is only needful to cause them to hold up such a photograph (about as large as a half dollar) at the distance of distinct vision, 10 inches, and then look at the Moon through it. At once her size dwindles away; we have established a standard of comparison, and see how great the deception was. In another way any one who has a spy-glass mounted on a stand can convince himself of the same thing. If the instrument magnify only 6 or 8 times, on looking through it at the Moon, she seems to be smaller than to the naked eye, possibly not larger than a penny. But if while one eye is still kept at the eye-piece of the telescope the other be opened, two moons are scen, a small one not as large as a pea, and another 6 or 8 times as great. By shutting first one eye and then the other, it can be shown that the small one is that seen by the naked eye. After repeating such an experiment several times the effect is permanent, the Moon looks always small, but if only once performed on going away from the telescope we again delude ourselves. In producing this photograph on the table, 21 inches in diameter, a magnifying power of about 200 has been used, and yet it seems no larger than half the rising Moon. But why is it then, if the size is the same in both cases, that we do not see with the naked eye the craters and cones and other parts as we see them here. No one is apt to amuse himself with imagining the face of a man in the Moon depicted on this paper; his attention is too much occupied with a multiplicity of details far more interesting. Not much reasoning is required to satisfy the mind that the greater distinctness of parts must arise from the fact that the photograph is a magnified representation. The Moon varies in her distance from the Earth considerably at different times. She should seem, therefore, on some occasions, much greater in size to us than on others. And yet who remarks the change in apparent diameter. A series of photographs taken on various occasions vary in size very materially, and bring this fact before us in a forcible manner. Yet the eye commits in this case a sin of omission. In yet another instance the unreliability of the senses is shown when not corrected by reason. We see the Moon and Stars before they have risen and after they have set. We never see them in their true positions, except in the rare case when they are directly overhead. The refractive action of the air lifts them out of their places, and astronomers in measuring the position of celestial bodies have to make a correction for this disturbance. It is generally supposed that we see in a straight line, but in looking at these bodies the light has reached the eye through a curved path. In reasoning then on such a subject as that which has occupied us this evening, we are admonished not to let our senses and imagination carry us away. Do not speculate on the nature of beings on other spheres as some have done, and attribute to them a variety of qualities corresponding to their supposed surroundings. Do not, with Fontenelle, give to the inhabitants of the hot planets, Mercury and Venus, characteristics in an exaggerated degree like those possessed by the inhabitants of our warm climates, doubting not that Venus is the seat of an empire where ardent affection rules, while in Mercury the vivacity of the inhabitants is so great that it is the Insane Asylum of the Universe; from the coldness of Jupiter and Saturn imagining that they are peopled with phlegmatic and slow-moving inhabitants. Do not propose for comets the function of penal | I can not believe that on our little globe alone, settlements for the planets, their wretched inhabitants being whirled, for sins committed, through fierce extremes of heat, now approximating the sun and made two thousand times as hot as molten iron, now traversing space 100° below zero. A calm consideration of the facts collected on this subject, after due weight has been given to the able arguments advanced on either side, would seem to lead to the following conclusions: First, we have reason to know that the various bodies of the solar system have a composition resembling one another; on the Sun, the most unlikely of all, many of the elements of the Earth are found, iron, sodium, etc. This remark may be extended to the fixed Stars. among the infinity of worlds, life has been possible, because only on it surrounding circumstances have been favorable. It seems more in accordance with reason to believe that there may be on many other globes intelligent beings, formed on the same plan as we are, but differing, on some perhaps for the better, on others for the worse. On our own globe we see what an influence such conditions as heat, moisture, etc., have on the inhabitants of the various zones. At the poles, where man struggles with difficulty to procure a precarious livelihood, intellect is at a low ebb, and exhausts itself in efforts to obtain food; at the equator, amidst the bounteous provision on every hand, mind and body are oppressed by a languor that seems only broken by the passions. In the temperate zone, our own happy latitude, the seasons conduce to activity; but thoughts of subsistence need not occupy all the time, enough can be spared to originate the most sublime ideas in science and the arts. It must be thus in the Third, we may be sure that Nature, opera- universe; though the general plan is the same ting upon like substances by similar laws, will throughout, there may be worlds that have ever produce the same results. There is a never passed the state in which the earth was unity of scheme pervading the universe, there in early geological times, while on others conare immortal types or exemplars, the Divine spiring circumstances may have allowed life to Ideas, according to which things are framed | develop even beyond our standard, and to reach with an infinite variety of modifications, de-a point that we may hope in the future to atpending on the surrounding physical conditions. I tain. Second, we feel satisfied that the same laws which rule the solar system rule the Universe; in the case of the law of gravity a demonstration can be easily offered, the binary Stars revolving around their common centre of gravity according to it. THERE is a wrinkled old man With thin and silvery hair, THE SPECTRE.. A lean and withered old man, Unseen of the people I meet. His cheeks are hollow with age; The face of this wrinkled old man. When Youth's bright summer is past, And the dreams that we dreamed are fled; And the hopes we cherished are dead; He stands by the mother who kneels And the lips that so sweetly smiled; Uplifted a moment in prayer, A likeness to him you may trace Imprinted indelibly there. Unseen he raises the latch, And creeps past the crazy door, His place at the master's right hand- He counts not the moments that pass, And drinks from the master's own glass. Though aged he never has known Youth's promise or manhood's prime, There is but one house that I know He shall find neither rest nor a home. "EASTER LILIES." HE triumphal Easter anthem filled the dark hazel eyes, who lingered at the font and asked for a flower. And he smiled politely as he offered her a cluster of dazzling lilies, glit Tchurch, and seemed to drift through arch tering like sunlight on snow. and architrave up to the very throne of God. The very building, with its cold, gray-stone walls, thrilled and pulsated with tuneful sound, and upon that joy-tide many a desolate soul floated upward nearer to heaven than ever before. Mrs. Thorne leaned back wearily in her pew, as if the strain uttered nothing that could reach her heart: "Christ the Lord has risen to-day!" She speculated vaguely about it, as she did about most things: it did not touch her-it was a dim and distant thing, like a story in Grecian History. And there was a fierce struggle in her innermost heart, a strange purpose with which she was wrestling, a horrible, haunting idea that rose again and again, like a vexed ghost, and would not be laid, which shut her eyes to the heavenly vision and her ears to celestial harmonies. The Easter flowers filled the font, and made a summer atmosphere of bloom and fragrance. Lilies, waxen white, yet with a sun-tinge in them; large golden-dusted cymes of laburnums, with feathery moss dewy and glistening; fragrant pale-blue mignonnette that sent a breath of balm through the aisles like incense; and some rosecolored blooms warming the whole. Mrs. Thorne had an appreciation for the lovely coloring of these, for she had an artist's eye. She had earned her bread by painting once, and had been "good at her art for a woman," they said. For five years she had not touched pencil or brush, for it was just five years to-day since she had married John Thorne, M.D. At last the service was over, the last words died away on the air-a hushed stillness, and then a subdued rustling showed that the people were going. Mrs. Thorne sat still as one in a dream. She had come in expecting something, some hope or comfort perhaps, which she had not received. Was there no blessing there for her? Other people brought their burdens there and found them roll away as Christian's did at the foot of the cross. Why did such an idle fiction haunt her? Christ, if there was a Christ, sat afar off, beyond the sunsets, and the cries and groans of the desolate never pierced that vast expanse of ether. She got up drearily then, for the young minister stood waiting in the chancel, and went forward. She would take something with her, if only a flower-something sweet and fresh and natural, that might whisper. Hush! that thought again. How kind and mild he looked! Perhaps he could minister to a mind diseased. Perhaps there was some good in the old Romish confessional after all. But this was a Protestant church. Margaret Thorne smiled grimly as she imagined how those mild blue eyes would dilate with surprise if she threw herself passionately at his feet and poured out all her thoughts, her wild regrets, her half-formed purposes, her skeptical doubts. Instead of this the minister only saw a stately-looking lady with rather eager, Mrs. Thorne did not go home. She turned instead out of the close, compact little town, and walked with tireless feet on and on, till the pavements came to an end, and straggling lanes, beginning to have a tender greenness hovering over them, lay before her. The distant hills shone yellowish gray or dimmed away into silver. The trees, with their delicate tracery of boughs against the blue sky, held each their store of different-colored buds half unfolded; the rock maples, with their salmon-colored leaves; white and red oaks and the birches spreading out a pale-green mist before a grove of sombre pines. Clusters of white dog-wood starred the woods, and pink columbines festooned the trees. Careless of the wet, Mrs. Thorne penetrated through the damp, sedgy ground to a stream that ran in the distance, treading on fairy-like mosses with slender, scarlet-tipped stems, some holding tiny brown cups like acorns, or gay dots of crimson flowers. All was clothed in the beautiful verdure of spring. Then the birds! a whole summer of joy and sunshine lay before them, and they kept high carnival. Margaret Thorne sat down on a bit of gray rock and watched a goldfinch rocking itself in the thin, sunny branches of a white birch that pulsated in the wind. She half rocked herself also, and murmured some lines that had echoed through her heart the whole morning: wild, wild wind, wilt thou never cease thy sighing? Dark, dark night, wilt thou never pass away? Thy Lent is past, thy Passion, but not thine Easter Reader! you And so she sat through all the long April after- When the slant sunbeams lay on the ground penetrating the long shadows of the trees she rose to go. She was weary with the contest; but calm-calm as if her heart, like her hopes, had died within her-"and she pitied her own heart, as if she held it in her hand." The lights were beginning to stir the town as she reached it, like friendly eyes to greet her; but she hurried blindly on with shuddering chills to the prim red brick house that was her home. "Dr. Thorne" decorated the brass plate on the door, and the light of a street-lamp |