an appropriation for it twice as great as the minister asked for, and thus provided not only for the necessary repairs, but for the entire re-construction of the smaller buildings used by the observers. The Deputies soon afterwards furnished the establishment with its vast, convenient, and richly decorated amphitheatre, which an expert architect has happily united with the other portions of the edifice, and into which a taste for astronomy constantly draws a numerous audience. The new structures destined for meridian observations happily unite convenience and utility with elegance, and leave absolutely nothing to be desired.

In former days, besides the dilapidation of the principal structure, another thing grieved the French visiter. The instruments in use were almost exclusively of foreign origin. The telescopes, for instance, bore the names of Campani, Borelli, Hartzocker, Huyghens, Dollond, and Short; the mural and transit instruments, and the great repeating circles, were the productions of Sisson, Bird, Ramsden, and Reichenbach. The astronomical clocks alone came from the workshops of our own artists. But now, all the instruments in the Paris observatory are of French manufacture. We have not sacrificed scientific exactness to national pride, which would have been an act of great folly, but we still find upon the walls and the massive piers the magnificent graduated circles, the transit instruments and equatorials, of Fortin and Gambey; and in the vast halls of the old building, the great achromatic telescopes manufactured by the skilful hands of Lerebours and Cauchoix. And how was this great change effected? The answer is a very simple one. The French artists were told to pay no heed to the almost universal opinion respecting an innate superiority which the English and German workmen possessed over them. This advice was followed, and the success of the trial surpassed all our hopes. In France, to venture is almost the same thing as to succeed.

For some years, all the governments of Europe seem to have acted in concert in improving their old observatories and creating new ones. In England, Greenwich, already so justly celebrated, has been much enlarged; and the observatories of Edinburgh, Cambridge, Oxford, Dublin, and Armagh vie with that which Flamstead, Halley, Bradley, Maskelyne, and Pond have made, illustrious, and which is still happily in very good hands. Similar establishments have been erected, on a great scale, at the Cape of Good Hope, at Sydney in New Holland, and at Madras. The Sicilian government, besides its renowned edifice at Palermo, to which Piazzi, at the beginning of this century, gave so much fame, has lately constructed a fine observatory near Naples, at Capo di Monte; and another, for observations in meteorology and physical science, is rising on the flanks of Vesuvius. The observatories of Florence, Milan, Padua, Turin, and Vienna might perhaps be criticised if viewed only as buildings; but the number and beauty of the instruments in them deserve all praise. All the world knows of the fine observatories, most of them new, at Brussels, Geneva, Altona, Munich, Göt

tingen, and Hamburg. In Prussia, the course of the stars is studied, under government auspices, at Bonn, Breslau, and Königsberg; and in this general rivalry in favor of the most magnificent of all sciences, Russia has placed herself in the first rank. Not content with very useful observatories at Dorpat, Abo, Kieff, Kazan, and Nicolaïeff on the Black Sea, she has just erected near Petersburg, on the hill of Pulkova, a model establishment. This central observatory of Russia has cost more than 2,000,000 of roubles; among its fine instruments is a telescope purchased at Munich for 80,000 roubles.

If some narrow minds conceive that so many observatories are useless, we can undeceive them by showing that the field of science has enlarged itself yet more rapidly than the means of investigation. Confining ourselves at first to those stars which are always visible, we find that more than 150,000 of them, formerly called fixed stars, are subject to movements which need to be continually measured with great exactness. Millions of stars, also, hitherto despised on account of their excessive smallness, now draw the attention of astronomers, and promise to unveil the most hidden wonders of the firmament. As for the comets, visible for so brief a period that we must almost steal a sight of them, protection is needed in Europe against the continuously misty atmosphere, which, at a given place, often renders any observation impossible for weeks together. Besides, is it not natural, that, in the nineteenth century, every nation should have the noble ambition to take a direct part in those astronomical victories of which men have most reason to be proud, on account of their certainty, their magnificence, and their usefulness?

Again, the vast improvements which are making in the construction of telescopes, achromatic glasses, and large graduated instruments, have contributed even more than the progress of astronomy or the ambitious eagerness of all European governments towards causing new observatories to be built, and the form and arrangement of old ones to be modified. The first spy-glasses of the poor optician of Middlebourg, who invented these wonderful instruments, had a focal distance of only one foot and a half. Those with which Galileo discovered the satellites of Jupiter, and the phases of Venus, multiplied the object hardly seven times. Huyghens and Cassini had telescopes which, with a focal distance of 24 feet, multiplied the object a hundred times. Afterwards, Auzout made an object-glass that had a multiplying power of 600, the focal distance being 300 (French) feet; but as we have already said, the use of an instrument as lofty as the dome of the Hotel of the Invalids, in spite of a thousand ingenious artifices, is obstructed by innumerable difficulties. The discouraged opticians, following the example of Newton, turned their attention to reflecting telescopes.

At length, in 1758, the son of a French refugee in England, John Dollond, achieved that which Newton had declared to be impossible, and produced telescopes which gave the images of heavenly bodies without those colored

borders which all simple object-glasses had created. Achromatic glasses of small dimensions, which had as great a multiplying power as the instruments 200 or 300 feet long, of Campani, Borelli, and Auzout, at once monopolized the attention of men of science. As the English alone could make flint glass without striæ, they were able to make achromatic glasses for the whole world. But they could not fabricate such lenses of more than six inches opening. The images thus created not having light enough to support the requisite multiplying power, recourse was again had to reflecting telescopes, and those colossal machines were made which have immortalized Herschel. A Swiss workman, in a glass manufactory near Munich, succeeded in making flint glass without striæ, and science then turned again to refracting telescopes. Incited by the skill with which Frauenhofer had used this glass, the English government endeavored, but in vain, to regain possession of a branch of industry which had fallen out of its hands. The most powerful instruments now in use, even in the English observatories, came from the workshops of Paris and Munich. The greatest known object-glass has 15 inches opening. It seems as if the power of such an instrument ought to be equalled, if not surpassed, by reflecting telescopes of attainable magnitude. In truth, a wealthy Irish nobleman, Lord Rosse, has applied, with infinite zeal and remarkable skill, enormous sums in attempts to construct such telescopes of greater dimensions than any yet known.

Things were in this state, when two glass-makers, Guinand and Bontemps, presented to the Academy of Sciences masses of crown and flint glass 22 inches in diameter, which appeared free from bubbles and striæ. The same artists engaged to furnish similar masses even three feet in diameter. Opticians have, also, generously offered to scientific societies the necessary mechanical means to shape, temper, and polish these gigantic glasses. Finally, the most eminent artist of our country has offered to direct this labor. In a very short time, if the Chamber adopts the proposition now made to it by the ministry, French astronomers will perhaps turn towards the skies telescopes superior to everything of the kind which now exists, superior even to what the most glowing imaginations would have dared to hope for, a year ago. Meanwhile, the parallactic mounting and the revolving roof of the eastern tower will enable us to make good use of several telescopes, which the difficulty of managing has hitherto rendered useless.

Are the discoveries foreshadowed by such grand instruments important enough to justify so much zeal and expense. Let us cite a few facts, and the Chamber may then answer this question for itself.

Till very lately, we had not succeeded in determining the actual distance of a single star. All that astronomers could establish was a limit within which not one of these stars could be situated. Now, thanks to the great telescopes of which we shall soon have the use, the true distance of ONE star is known. The little star called 61 Cygni is so far from the earth, that it requires ten years for its light to reach us; so that, if the star were suddenly annihilated, it

would still be seen for ten years after the catastrophe. Remember that light travels 191,000 miles in a second, that there are 86,400 seconds in a day, and 365 1-4 days in a year. The product of these three numbers, multiplied by ten, gives us the distance in miles which separates us in a straight line from 61 Cygni. Astronomers may well boast of such a result, and desire to apply their magnificent measuring operations to other stars. Large telescopes, of parallactic mounting and high magnifying power, will serve to perfect the observations upon the double stars. It is now known that the stars of nearly all these binary groups are dependent upon each other; they form systems composed of suns, usually colored, and turning around their common centre of gravity. The exact measurement of these movements of rotation, combined with the determination of the actual distance of the two stars, will lead mathematically to a knowledge of the sum of the two masses. When mathematicians and astronomers were enabled to prove with absolute certainty, that the mass of the sun is 355,000 times as great as that of the earth, every one was struck with astonishment. But the result was by no means so wonderful or so difficult of attainment as the one now proposed. Then, the problem was to ascertain the bulk of a heavenly body which appears even to the naked eye as a vast globe, around which the earth revolves, and which governs by its attraction, -that is, by an action dependent on its mass, all the planetary movements. Every one can here dimly perceive a priori connections and relations which ought to lead to the desired result. Now, the object is to ascertain the bulk of suns belonging to other systems; of suns placed at such distances as to confound the imagination; of suns which appear, even through the telescope, of no appreciable diameter; of suns which the mere thickness of a spider's thread veils from the eye of the observer. Here the force of science will appear in all its majesty.

With such a telescope as we now speak of, astronomy will find a field of research, as yet almost untouched, in the vast and variously shaped nebulæ, which are scattered all over the heavens. It will observe the gradual concentration of the phosphorescent matter; it will mark the epochs when it assumes a circular shape, when the luminous central nucleus first appears, when this nucleus, having become very bright, will remain surrounded only by a slight nebulous halo, and when this halo also will be condensed. Then, the observer will have followed through all its phases the birth of a new star. Another quarter of the heavens will show us how the same stars gradually grow faint, and at last entirely disappear.*

Within the limits of our own system, also, a great telescope promises discoveries of another kind, and of no inferior interest. We yet know but little of the atmosphere of Venus, or of the lofty mountains with which this

*The truth of the nebular hypothesis is here taken for granted; but if the recent accounts of discoveries made through Lord Rosse's telescope are correct, this hypothesis is only a splendid dream.

globe, nearly as large as the earth, appears to be covered. The snowy spots which periodically appear, increase, diminish, and disappear, first at one, and then at the other pole of rotation of Mars, according as the sun is in this or that hemisphere of the red planet, have not been sufficiently studied. Though Jupiter has not yet been carefully examined with powerful telescopes, we know that in the equinoctial regions of this planet there are winds like our trade-winds; that the atmosphere there undergoes enormous perturbations; and that clouds there are sometimes borne along at the speed of 250 miles an hour. If these curious results have been obtained with our present imperfect means of observation, what may we not expect from diligence united with power? The mysterious ring of Saturn, — that continuous bridge without piles, 30,000 miles broad, 250 miles thick, and everywhere distant 20,000 miles from the planet which it surrounds, — certainly reserves capital discoveries for one who can examine it continuously with a high magnifying power. The continued observation of the brilliant satellites of Jupiter has so enriched science, that we may reasonably expect much from an uninterrupted examination of the satellites of Saturn and Uranus. A study of the continual changes of form which comets undergo ought to enlighten us respecting the physical constitution of celestial space. If these inquiries as yet have made but little progress, the fault must be imputed to the feebleness of our telescopes.

Let us now take a rapid view of what may reasonably be expected from the application of much improved instruments to the observation of the Moon. 1,093 mountains upon its surface have been exactly measured. One of these lunar mountains, Doerfel, is 25,000 feet high; another, Newton, is 24,000 feet; a third, Casatus, is 22,500 feet. The crater-like formation of most of the moon's surface, also, has been carefully observed; the depth of each crater and the altitude of the central peak are now exactly known; and astronomers have obtained these results with a multiplying power not exceeding 200. May we not have great hopes, then, of a telescope the illumination of which will permit us to use a multiplying power of 6,000, and through which we can observe a lunar mountain as fully as we now can see Mont Blanc from Geneva? In 1843, Dr. Robinson examined the moon with a reflecting telescope, three feet in diameter, belonging to Lord Rosse; its illumination was only one fourth as great of a refractor of three feet opening, and the multiplying power was but moderate. Yet this astronomer has already pressingly invited the naturalists to go to Parsontown in Ireland, in order to study the physical constitution of the moon, assuring them, that they would gain entirely new information respecting the action, upon our globe, of the forces which govern the formation of volcanic regions.

If, after this long exposition of the uses of great telescopes, the Chamber will also remember that, in such a case, the unexpected discoveries are always the most numerous, most fruitful, and most brilliant, it will see why its Committee unanimously recommends, that an appropriation of $19,000 should be made for completing the Observatory of Paris.