nomical science becomes of interest to the merchant as well as to the student, and it is our purpose in this paper, in connection with a notice of the National Observatory, its origin, endowment, and administration, to present a brief sketch of the astronomical movement among ourselves, and as much of the general history of the science as we may deem of interest, or for which the material may be present. Astronomy, in its present improved state, is too apt to be considered as a contemplation merely-a scientific contemplation, indeed, and a devout one also-but separated entirely from this working-day world, and belonging, like music and painting, to that class of knowledge whose domain is rather in the air than on the earth-in the ideal than the actual world. At the risk of being thought superfluous, and as a curative of this notion, which is too generally prevalent, we will venture to present an historical sketch of this science, considered merely as a practical one. The sciences have all had their origin in some one or other of the inherent wants of our species, the subject and domain of each being only varied by the nature of the desideratum which it was intended to supply. Among our primeval ancestors, a tempest or a rain of unusual length would suggest the comfort of shelter, and ere long produce a class of rude architects and builders: disease and accidental injury require remedy, hence leech-craft and its fellows: the growth and decay of vegetation would by degrees indicate the appliances necessary for its preservation and renewal; while the evident capability and inclination which we possess to injure each other would soon direct attention to the means of defense, hence the shield and spear, the mound and trench, the armourer and engineer. It is neither fanciful nor irreligious to trace in this way the source and division of all the branches of human knowledge, or to follow them in their subsequent stages of development. The simple discoveries making the basis and ground-work of each separate science, would be transmitted as property among the first races, (our mental, like our physical possessions, increasing at first mainly by inheritance,) until, in process of time, a body of facts and institutes had been accumulated in the hands of a distinct class or caste of the community, who would by this means obtain a powerful influence over their fellows. In the hands of these primitive doctors science would become connected with education, with government, and religion; while the emoluments and honors of its votaries would insure them leisure for extending and perfecting their researches. If we trace astronomy to its origin, according to this genealogical hypothesis, its first office will be found in the supply of a very primeval and important want, to wit: the determination of a measure of time, and the length of the year. This want has so long disappeared from among us, that we can scarce conceive of a time when it existed at all, or of the process by which it has been obliterated; yet it required long ages of observation, under the serene and clear skies of eastern countries, to arrive at the determination of a period by which the return of the seasons could be predicted. Years of 304, 354, 360, and 365 days preceded at long intervals the establishment of the Julian year, to the discussion and perfecting of which was brought all the accumulated knowledge of the East; and even that period, fixed with so much care, was so imperfect that in the sixteenth century it required a correction of ten days, to prevent March from assuming the skies and influences of April, and pushing all the other months from their rightful place. The first function of astronomy, therefore, was to furnish a measure of time, by which the returns of the seasons might be foretold, and the labors of agriculture regulated. To effect this purpose many and long tentatives were necessary, during which, and as necessary auxiliaries, arose all those attendant sciences which deal with quantity, with space, and their abstract relations. Aided by them astronomy now comprehends all the complications of planetary motion, has resolved them into their simplest forms, and presents to us, in the whole visible universe with which we are surrounded, but the development, upon an infinite scale, of the forces, masses, and motions with which, in all stages of our existence, we have been familiar. Its origin, therefore, has been of the most direct and simplest character; its progress has been marked by the creation of other branches of knowledge of great use and dignity, while in its present mature state it presents the most extended field for intellectual exertion, and the highest measure of intellectual power. The greatest pleasure of which our nature is susceptible arises from the acquisition or perception of new truths, and we can conceive of no more transcendant exercise of this faculty than is found when we first discover that the circumscribed motions with which we can impress smaller masses of matter for our own uses, are all but workings of the same invisible force, and governed by the same laws which obtain in the immensities of space. That indeed the whole of this visible universe, so complicated in its appearances, is, like our own microcosm, produced by the arrangement of material masses placed in certain relations to each other, and governed by perfect but unseen agencies, whose nature and operation are as inscrutable as the perceptions of our own minds, or the acts of our own souls. But apart from the exact sciences, whose origin may be traced directly to the cultivation of astronomy, there are other more ethereal influences which have been derived from the same source, and whose effects are still indelibly fixed upon the kindred arts of our own age. In the infancy of the world the ever-present heaven was an unfathomable but beloved mystery, the contemplation of which awoke both awe and worship, and the simple but earnest fathers of our race peopled it with their own imaginings. "The star that bids the shepherd fold" became the home of some translated mortal, and the constellation set to mark the return of spring was hailed as the benignant power which produced it. Out of these fervid but solemn dreams arose that world of myths, which still holds its place among us, though the faiths which created them have long since disappeared. "The intelligible forms of ancient poets, Or forest, by slow stream or pebbly spring, Or chasm, or wat'ry depth: all these have vanished- Even after the establishment of the true faith had obliterated all worship of these divinities of an earlier age, we see in the almost universal prevalence of judicial astrology, a science which dates from that period, strong proof of the reluctance with which men yielded up their belief in the celestial influences. In this science the planets were consulted as indicating the decrees of destiny. And though some of its votaries may have been believers in its truth, there is but little doubt that the greater number regarded • Coleridge, from Schiller's Wallenstein. it only as a shelter and disguise in which, protected by the shadows of the old mythology, and feared for pursuits, deemed both preternatural and profane, they found leisure to continue their observations on the heavens; for it is not being either too critical or too credulous to see, in the practice of this factitious science, a provision for preserving the germs of astronomical science through the dark peried of feudal barbarism. Astrology was, then, to astronomy what alchemy was to chemistry-the husk or rind which preserved the seed for its season.* These relative effects of astronomy upon the knowledge and belief of a precedent age should not be less appreciated because they have no place in our own. On the revival of letters, we find astronomy resuming its pristine office, the adjustment of the measure of time and the length of the perfect year, the errors of the previous establishment having already become very apparent. The Christian era was generally adopted in the year 532, and the preservation of the calendar, or the office of keeping the festivals of the church in accordance with the year of the seasons, necessarily devolved upon the clergy. Among rude nations the most important use of any record of time is the apportionment of religious observances, and the principal epochs of any people are always found connected with their established ritual. The methods used by the clergy for preserving the year were kept profound secret until the middle of the fifteenth century. It is now apparent that they had adopted the latest and best authority, to wit: the Julian year, intercalating a day every fourth year, and fixing the high festival of Easter by the full moon immediately following the vernal equinox. The Julian year being, however, too long by a small quantity, its error had in process of time become so aggrandized, that in the fifteenth century the the Pascal moon, determined by the church, was evidently leaving the season to which it belonged. This defect becoming of general notoriety, Sextus IV., in 1474, invited to Rome the celebrated astronomer Jean Müller, better known now as Regiomontanus, in order that the aid of science might be had in the matter. Unfortunately, Regiomontanus died soon after, and things. remained as they were until 1582, when Gregory XIII. succeeded in establishing the calendar which has since born his name, and which was introduced into all Catholic countries soon after. Although the divisions of the new calendar were arranged by the old method of cycles, and the fictitious full moon of the Metonian cycle (which may differ from the real one two days) was retained, still the data then furnished by astronomers as to the absolute length of the year, enabled them to regulate the intercalations so as to prevent the accumulation of error, which had vitiated the former calendar. For scientific aid the Pontiff seems to have relied mainly upon the Calabrian astronomer Lullio; but this was the age of Copernicus, Tycho, Kepler, and Galileo, and the reformation of the calendar, though carried by the authority of the Church, was based upon astronomical determinations.§ "Astrology and improvements in the calendar long procured protection for astronomy from the secular and ecclesiastical powers, as chemistry and botany were long esteemed as purely subservient auxiliaries to the science of medicine."-Cosmos, vel. ii. + Regiomontanus had previously occupied himself with the calendar, and prepared an almanac in advance for the year 1474. It is the first ephemeris ever published. He died at Rome of the plague in 1476. "It is not generally known that Easter is regulated by a moon fictitious and imaginary, and not by the real one."-Arago du Calendrier. Copernicus, in soliciting protection from the Pope for his discoveries, makes the plea, "that the Church itself would derive advantage from his investigations on the length of the year and the movements of the moon."-Cosmos, vol. ii. The new calendar was not adopted in Protestant countries for a considerable time thereafter. In some parts of Switzerland it was imposed by force of arms, and in Poland it occasioned an insurrection. This was the era of religious reformation, and changes of the most evident utility proposed by one sect were certain to be resisted by the other. In England the change was not made till 1752. In that country it was also necessary to change the commencement of the year, which had previously been counted from the 25th of March, so that the year 1751 was without January, February, and a great part of March. The opponents of the measure in Parliament contended (alas, for the honesty of politicians!) that this change defrauded poor people of three months' wages, and Lord Chesterfield, one of its principal advocates, was attacked by a London mob, with cries of "Give us our three months." Changes in long-established customs are always made with difficulty. In France, up to the second restoration, (1815,) the clocks of Paris had been set by apparent time, (noon being counted from the passage of the sun over the meridian.) When mean time was substituted, an insurrection of the ouvriers was anticipated though it did not occur. Had the change not been made then, it would have been absolutely necessary now; for in a capital so benetted with railroads the continuation of the old method must have occasioned numberless and destructive accidents. We have been thus particular in tracing the history of the calendar, because its establishment marks the era at which public observatories were first instituted throughout Christendom; for though the Protestant countries refused to adopt the reckoning imposed by the Pontiff upon his spiritual subjects, yet the state of learning at that time did not permit them to overlook the matter altogether. If they refused to submit to authority, they were obliged to patronize investigation. For the purpose of settling permanently the length of the year, observatories were first endowed by all the principal nations in Europe. The Observatory of the Collegio di Romano was the only one existing at the time of the Gregorian reform, yet that event was followed almost immediately by other more active and better appointed institutions. The Observatory of Copenhagen was founded in 1637; Paris in 1664; Greenwich in 1675; Berlin in 1711, and St. Petersburg in 1725 -in all of which the proper arrangement of the calendar was recognized as the most important function. At the same period arose all those national academies which have been continued to our own day, and connected with which are found all the distinguished votaries of science of the intervening period. These academies were created as necessary adjuncts to the observatories, within whose circuit methods both of observation and computation might be thoroughly discussed and perfected. For although they have in later times extended their researches to every science, yet the cultivation of astronomy was the original and prime object of their establishment. At least, to this source they may all be traced, with the exception only of the Italian academies, which grew up with the revival of letters, and were at first devoted rather to art than to science. Thus far we have traced the practical uses of astronomy in reference to time-we must now follow them into the kindred realm of space. A certain amount of geographical knowledge is required among all nations who have affairs either of Commerce or of war; but in powerful and extensive States, more accurate and detailed information of this kind becomes necessary for the proper apportionment of taxes, and the general administration of the revenue; as at a certain stage of improvement the assessments on the value of land come to depend mainly upon superficial areas. The want of a correct basis for this purpose began to be felt in France about the year 1671, it being found then that seignioral limits had gradually enlarged in estimation as they receded from the capital, until the distances from Paris to any of the frontiers had increased about one-third, and Brest, with all the contiguous coast, was thrust about thirty leagues into the ocean.* At this time astronomical observations had so far improved as to be available for the determination of geographical position. The inaccuracy of the existing charts of the kingdom were represented to the king by the members of the academy, and in 1681 the first steps were taken for the construction of the great map of France, which was commenced soon after by the elder Cassini. The academy was charged with the execution of this work, in the progress of which the modern sciences of geodesie and topography may be said to have originated. The operations directed by the academy for the construction of the map of France had incidentally another important effect upon the science of the time. The theory of the solar system announced by Copernicus was for a long time disputed, one and a principal argument used against it being found in its disagreement with the literal signification of some passages of the Holy Scriptures. About the time of the commencement of the survey for the French map, the discoveries of Newton had been promulgated, one consequence of his universal principle being that the earth must be a spheroid, flattened at the poles. The basis of the French survey was a meridian extending through Paris from the ocean to the Pyrennees, whose length and the position of its extremities had at that time been determined. A comparison of the lengths of different portions of this line, with the differences of latitude, afforded a direct method of testing the truth of the Newtonian hypothesis, so far as it concerned the figure of the earth, and this comparison was instituted by the most distinguished astronomers of the time. Unfortunately, the methods used at first in the reduction of the work were so imperfect that they resulted in a confutation of the Newtonian system, and proved that the earth was elongated instead of flattened at the poles. On a recomputation by improved methods the contradiction vanished, and the system of the English philosopher received a practical confirmation. But from this circumstance a new direction and impetus was given to scientific investigation, and the determination of the figure of the earth, by measurements made on its surface, became the most important problem of the day. Distinguished astronomers were sent to measure arcs of the meridian in different latitudes in Lapland, Peru, and North America, the result of which not only put the Newtonian principles beyond cavil, but was the source of innumerable improvements in the construction of instruments and methods of calculation, and gave afterward to the French their decimal system of weight and measure, which promises at some day to become universal. While France had thus been more particularly occupied with the geography of her own domain, England entered upon a more general and wider field of operation. The foundation of her colonial power and policy, which have since been so immensely developed, had then just been laid, and her Commerce began to show itself in every quarter of the world. At such an epoch it was natural that the maritime interest should be held paramount, * Montucla, Historie des Mathematiques, vol. ii., p. 520. |