The Uses of Astronomy Part 2

a.s.sembled as we are, under your auspices, in this ancient and hospitable city, for an object indicative of a highly-advanced stage of scientific culture, it is natural, in the first place, to cast a historical glance at the past. It seems almost to surpa.s.s belief, though an unquestioned fact, that more than a century should have pa.s.sed away, after Cabot had discovered the coast of North America for England, before any knowledge was gained of the n.o.ble river on which your city stands, and which was destined by Providence to determine, in after times, the position of the commercial metropolis of the Continent. It is true that Verazzano, a bold and sagacious Florentine navigator, in the service of France, had entered the Narrows in 1524, which he describes as a very large river, deep at its mouth, which forced its way through steep hills to the sea; but though he, like all the naval adventurers of that age, was sailing westward in search of a shorter pa.s.sage to India, he left this part of the coast without any attempt to ascend the river; nor can it be gathered from his narrative that he believed it to penetrate far into the interior.

VOYAGE OF HENDRICK HUDSON.

Near a hundred years elapsed before that great thought acquired substance and form. In the spring of 1609, the heroic but unfortunate Hudson, one of the brightest names in the history of English maritime adventure, but then in the employment of the Dutch East India Company, in a vessel of eighty tons, bearing the very astronomical name of the _Half Moon_, having been stopped by the ice in the Polar Sea, in the attempt to reach the East by the way of Nova Zembla, struck over to the coast of America in a high northern lat.i.tude. He then stretched down southwardly to the entrance of Chesapeake Bay (of which he had gained a knowledge from the charts and descriptions of his friend, Captain Smith), thence returning to the north, entered Delaware Bay, standing out again to sea, arrived on the second of September in sight of the "high hills" of Neversink, p.r.o.nouncing it "a good land to fall in with, and a pleasant land to see;" and, on the following morning, sending his boat before him to sound the way, pa.s.sed Sandy Hook, and there came to anchor on the third of September, 1609; two hundred and forty-seven years ago next Wednesday. What an event, my friends, in the history of American population, enterprise, commerce, intelligence, and power--the dropping of that anchor at Sandy Hook!

DISCOVERY OF THE HUDSON RIVER.

Here he lingered a week, in friendly intercourse with the natives of New Jersey, while a boat's company explored the waters up to Newark Bay. And now the great question. Shall he turn back, like Verazzano, or ascend the stream? Hudson was of a race not p.r.o.ne to turn back, by sea or by land. On the eleventh of September he raised the anchor of the _Half Moon_, pa.s.sed through the Narrows, beholding on both sides "as beautiful a land as one can tread on;" and floated cautiously and slowly up the n.o.ble stream--the first ship that ever rested on its bosom. He pa.s.sed the Palisades, nature's dark basaltic Malakoff, forced the iron gateway of the Highlands, anch.o.r.ed, on the fourteenth, near West Point; swept onward and upward, the following day, by gra.s.sy meadows and tangled slopes, hereafter to be covered with smiling villages;--by elevated banks and woody heights, the destined site of towns and cities--of Newburg, Poughkeepsie, Catskill;--on the evening of the fifteenth arrived opposite "the mountains which lie from the river side," where he found "a very loving people and very old men;" and the day following sailed by the spot hereafter to be honored by his own ill.u.s.trious name.

One more day wafts him up between Schodac and Castleton; and here he landed and pa.s.sed a day with the natives,--greeted with all sorts of barbarous hospitality,--the land "the finest for cultivation he ever set foot on," the natives so kind and gentle, that when they found he would not remain with them over night, and feared that he left them--poor children of nature!--because he was afraid of their weapons,--he, whose quarter-deck was heavy with ordnance,--they "broke their arrows in pieces, and threw them in the fire." On the following morning, with the early flood-tide, on the 19th of September, 1609, the _Half Moon_ "ran higher up, two leagues above the Shoals," and came to anchor in deep water, near the site of the present city of Albany. Happy if he could have closed his gallant career on the banks of the stream which so justly bears his name, and thus have escaped the sorrowful and mysterious catastrophe which awaited him the next year!

CHAMPLAIN'S VOYAGE AND THE GROWTH OF COLONIES.

But the discovery of your great river and of the site of your ancient city, is not the only event which renders the year 1609 memorable in the annals of America and the world. It was one of those years in which a sort of sympathetic movement toward great results unconsciously pervades the races and the minds of men. While Hudson discovered this mighty river and this vast region for the Dutch East India Company, Champlain, in the same year, carried the lilies of France to the beautiful lake which bears his name on your northern limits; the languishing establishments of England in Virginia were strengthened by the second charter granted to that colony; the little church of Robinson removed from Amsterdam to Leyden, from which, in a few years, they went forth, to lay the foundations of New England on Plymouth Rock; the seven United Provinces of the Netherlands, after that terrific struggle of forty years (the commencement of which has just been embalmed in a record worthy of the great event by an American historian) wrested from Spain the virtual acknowledgment of their independence, in the Twelve Years'

Truce; and James the First, in the same year, granted to the British East India Company their first permanent charter,--corner-stone of an empire destined in two centuries to overshadow the East.

GALILEO'S DISCOVERIES

One more incident is wanting to complete the list of the memorable occurrences which signalize the year 1609, and one most worthy to be remembered by us on this occasion. Cotemporaneously with the events which I have enumerated--eras of history, dates of empire, the starting-point in some of the greatest political, social, and moral revolutions in our annals, an Italian astronomer, who had heard of the magnifying gla.s.ses which had been made in Holland, by which distant objects could be brought seemingly near, caught at the idea, constructed a telescope, and pointed it to the heavens. Yes, my friends, in the same year in which Hudson discovered your river and the site of your ancient town, in which Robinson made his melancholy hegira from Amsterdam to Leyden, Galileo Galilei, with a telescope, the work of his own hands, discovered the phases of Venus and the satellites of Jupiter; and now, after the lapse of less than two centuries and a half, on a spot then embosomed in the wilderness--the covert of the least civilized of all the races of men--we are a.s.sembled--descendants of the Hollanders, descendants of the Pilgrims, in this ancient and prosperous city, to inaugurate the establishment of a first-cla.s.s Astronomical Observatory.

EARLY DAYS OF ALBANY.

One more glance at your early history. Three years after the landing of the Pilgrims at Plymouth, Fort Orange was erected, in the center of what is now the business part of the city of Albany; and, a few years later, the little hamlet of Beverswyck began to nestle under its walls. Two centuries ago, my Albanian friends, this very year, and I believe this very month of August, your forefathers a.s.sembled, not to inaugurate an observatory, but to lay the foundations of a new church, in the place of the rude cabin which had hitherto served them in that capacity. It was built at the intersection of Yonker's and Handelaar's, better known to you as State and Market streets. Public and private liberality cooperated in the important work. The authorities at the Fort gave fifteen hundred guilders; the patroon of that early day, with the liberality coeval with the name and the race, contributed a thousand; while the inhabitants, for whose benefit it was erected, whose numbers were small and their resources smaller, contributed twenty beavers "for the purchase of an oaken pulpit in Holland." Whether the largest part of this subscription was bestowed by some liberal benefactress, tradition has not informed us.

NEW AMSTERDAM

Nor is the year 1656 memorable in the annals of Albany alone. In that same year your imperial metropolis, then numbering about three hundred inhabitants, was first laid out as a city, by the name of New Amsterdam.[A] In eight years more, New Netherland becomes New York; Fort Orange and its dependent hamlet a.s.sumes the name of Albany. A century of various fortune succeeds; the scourge of French and Indian war is rarely absent from the land; every shock of European policy vibrates with electric rapidity across the Atlantic; but the year 1756 finds a population of 300,000 in your growing province. Albany, however, may still be regarded almost as a frontier settlement. Of the twelve counties into which the province was divided a hundred years ago, the county of Albany comprehended all that lay north and west of the city; and the city itself contained but about three hundred and fifty houses.

[Footnote A: These historical notices are, for the most part, abridged from Mr. Brodhead's excellent history of New York.]

TWO HUNDRED YEARS.

One more century; another act in the great drama of empire; another French and Indian War beneath the banners of England; a successful Revolution, of which some of the most momentous events occurred within your limits; a union of States; a Const.i.tution of Federal Government; your population carried to the St. Lawrence and the great Lakes, and their waters poured into the Hudson; your territory covered with a net-work of ca.n.a.ls and railroads, filled with life and action, and power, with all the works of peaceful art and prosperous enterprise with all the inst.i.tutions which const.i.tute and advance the civilization of the age; its population exceeding that of the Union at the date of the Revolution; your own numbers twice as large as those of the largest city of that day, you have met together, my Friends, just two hundred years since the erection of the little church of Beverswyck, to dedicate a n.o.ble temple of science and to take a becoming public notice of the establishment of an inst.i.tution, destined, as we trust, to exert a beneficial influence on the progress of useful knowledge at home and abroad, and through that on the general cause of civilization.

SCIENTIFIC PROGRESS.

You will observe that I am careful to say the progress of science "at home and abroad;" for the study of Astronomy in this country has long since, I am happy to add, pa.s.sed that point where it is content to repeat the observations and verify the results of European research. It has boldly and successfully entered the field of original investigation, discovery, and speculation; and there is not now a single department of the science in which the names of American observers and mathematicians are not cited by our brethren across the water, side by side with the most eminent of their European contemporaries.

This state of things is certainly recent. During the colonial period and in the first generation after the Revolution, no department of science was, for obvious causes, very extensively cultivated in America--astronomy perhaps as much as the kindred branches. The improvement in the quadrant, commonly known as Hadley's, had already been made at Philadelphia by G.o.dfrey, in the early part of the last century; and the beautiful invention of the collimating telescope was made at a later period by Rittenhouse, an astronomer of distinguished repute. The transits of Venus of 1761 and 1769 were observed, and orreries were constructed in different parts of the country; and some respectable scientific essays are contained and valuable observations are recorded in the early volumes of the Transactions of the Philosophical Society, at Philadelphia, and the American Academy of Arts and Sciences at Boston and Cambridge. But in the absence of a numerous cla.s.s of men of science to encourage and aid each other, without observatories and without valuable instruments, little of importance could be expected in the higher walks of astronomical life.

AMERICAN OBSERVATIONS.

The greater the credit due for the achievement of an enterprise commenced in the early part of the present century, and which would reflect honor on the science of any country and any age; I mean the translation and commentary on Laplace's _Mecanique Celeste_, by Bowditch; a work of whose merit I am myself wholly unable to form an opinion, but which I suppose places the learned translator and commentator on a level with the ablest astronomers and geometers of the day. This work may be considered as opening a new era in the history of American science. The country was still almost wholly deficient in instrumental power; but the want was generally felt by men of science, and the public mind in various parts of the country began to be turned towards the means of supplying it. In 1825, President John Quincy Adams brought the subject of a National Observatory before Congress. Political considerations prevented its being favorably entertained at that time; and it was not till 1842, and as an incident of the exploring expedition, that an appropriation was made for a depot for the charts and instruments of the Navy. On this modest basis has been reared the National Observatory at Washington; an inst.i.tution which has already taken and fully sustains an honorable position among the scientific establishments of the age.

Besides the inst.i.tution at Washington, fifteen or twenty observatories have within the last few years, been established in different parts of the country, some of them on a modest scale, for the gratification of the scientific taste and zeal of individuals, others on a broad foundation of expense and usefulness. In these establishments, public and private, the means are provided for the highest order of astronomical observation, research, and instruction. There is already in the country an amount of instrumental power (to which addition is constantly making), and of mathematical skill on the part of our men of science, adequate to a manly compet.i.tion with their European contemporaries. The fruits are already before the world, in the triangulation of several of the States, in the great work of the Coast Survey, in the numerous scientific surveys of the interior of the Continent, in the astronomical department of the Exploring Expedition, in the scientific expedition to Chili, in the brilliant hydrographical labors of the Observatory at Washington, in the published observations of Washington and Cambridge, in the Journal conducted by the Nestor of American Science, now in its eighth l.u.s.trum; in the _Sidereal Messenger_, the _Astronomical Journal_, and the _National Ephemeris_; in the great chronometrical expeditions to determine the longitude of Cambridge, better ascertained than that of Paris was till within the last year; in the prompt rectification of the errors in the predicted elements of Neptune; in its identification with Lalande's missing star, and in the calculation of its ephemeris; in the discovery of the satellite of Neptune, of the eighth satellite of Saturn, and of the innermost of its rings; in the establishment, both by observation and theory, of the non-solid character of Saturn's rings; in the separation and measurement of many double and triple stars, amenable only to superior instrumental power, in the immense labor already performed in preparing star catalogues, and in numerous accurate observations of standard stars; in the diligent and successful observation of the meteoric showers; in an extensive series of magnetic observations; in the discovery of an asteroid and ten or twelve telescopic comets; in the resolution of nebulae which had defied every thing in Europe but Lord Rosse's great reflector; in the application of electricity to the measurement of differences in longitude; in the ascertainment of the velocity of the electro-magnetic fluid, and its truly wonderful uses in recording astronomical observations. These are but a portion of the achievements of American astronomical science within fifteen or twenty years, and fully justify the most sanguine antic.i.p.ations of its further progress.

How far our astronomers may be able to pursue their researches, will depend upon the resources of our public inst.i.tutions, and the liberality of wealthy individuals in furnishing the requisite means. With the exception of the observatories at Washington and West Point, little can be done, or be expected to be done, by the government of the Union or the States; but in this, as in every other department of liberal art and science, the great dependence,--and may I not add, the safe dependence?--as it ever has been, must continue to be upon the bounty of enlightened, liberal, and public-spirited individuals.

THE DUDLEY OBSERVATORY.

It is by a signal exercise of this bounty, my Friends, that we are called together to-day. The munificence of several citizens of this ancient city, among whom the first place is due to the generous lady whose name has with great propriety been given to the inst.i.tution, has furnished the means for the foundation of the Dudley Observatory at Albany. On a commanding elevation on the northern edge of the city, liberally given for that purpose by the head of a family in which the patronage of science is hereditary, a building of ample dimensions has been erected, upon a plan which combines all the requisites of solidity, convenience, and taste. A large portion of the expense of the structure has been defrayed by Mrs. Blandina Dudley; to whose generosity, and that of several other public-spirited individuals, the inst.i.tution is also indebted for the provision which has been made for an adequate supply of first-cla.s.s instruments, to be executed by the most eminent makers in Europe and America; and which, it is confidently expected, will yield to none of their cla.s.s in any observatory in the world.[A]

[Footnote A: Prof. Loomis, in _Harper's Magazine_ for June, p. 49.]

With a liberal supply of instrumental power; established in a community to whose intelligence and generosity its support may be safely confided, and whose educational inst.i.tutions are rapidly realizing the conception of a university; countenanced by the gentleman who conducts the United States Coast Survey with such scientific skill and administrative energy; committed to the immediate supervision of an astronomer to whose distinguished talent had been added the advantage of a thorough scientific education in the most renowned universities of Europe, and who, as the editor of the _American Astronomical Journal_, has shown himself to be fully qualified for the high trust;--under these favorable circ.u.mstances, the Dudley Observatory at Albany takes its place among the scientific foundations of the country and the world.

WONDERS OF ASTRONOMY.

It is no affected modesty which leads me to express the regret that this interesting occasion could not have taken place under somewhat different auspices. I feel that the duty of addressing this great and enlightened a.s.sembly, comprising so much of the intelligence of the community and of the science of the country, ought to have been elsewhere a.s.signed; that it should have devolved upon some one of the eminent persons, many of whom I see before me, to whom you have been listening the past week, who, as observers and geometers, could have treated the subject with a master's power; astronomers, whose telescopes have penetrated the depths of the heavens, or mathematicians, whose a.n.a.lysis unthreads the maze of their wondrous mechanism. If, instead of commanding, as you easily could have done, qualifications of this kind, your choice has rather fallen on one making no pretensions to the honorable name of a man of science,--but whose delight it has always been to turn aside from the dusty paths of active life, for an interval of recreation in the green fields of sacred nature in all her kingdoms,--it is, I presume, because you have desired on an occasion of this kind, necessarily of a popular character, that those views of the subject should be presented which address themselves to the general intelligence of the community, and not to its select scientific circles. There is, perhaps, no branch of science which to the same extent as astronomy exhibits phenomena which, while they task the highest powers of philosophical research, are also well adapted to arrest the attention of minds barely tinctured with scientific culture, and even to teach the sensibilities of the wholly uninstructed observer. The profound investigations of the chemist into the ultimate const.i.tution of material nature, the minute researches of the physiologist into the secrets of animal life, the transcendental logic of the geometer, clothed in a notation, the very sight of which terrifies the uninitiated,--are lost on the common understanding. But the unspeakable glories of the rising and the setting sun; the serene majesty of the moon, as she walks in full-orbed brightness through the heavens; the soft witchery of the morning and the evening star; the imperial splendors of the firmament on a bright, unclouded night; the comet, whose streaming banner floats over half the sky,--these are objects which charm and astonish alike the philosopher and the peasant, the mathematician who weighs the ma.s.ses and defines the orbits of the heavenly bodies, and the untutored observer who sees nothing beyond the images painted upon the eye.

WHAT IS AN ASTRONOMICAL OBSERVATORY?

An astronomical observatory, in the general acceptation of the word, is a building erected for the reception and appropriate use of astronomical instruments, and the accommodation of the men of science employed in making and reducing observations of the heavenly bodies. These instruments are mainly of three cla.s.ses, to which I believe all others of a strictly astronomical character may be referred.

1. The instruments by which the heavens are inspected, with a view to discover the existence of those celestial bodies which are not visible to the naked eye (beyond all comparison more numerous than those which are), and the magnitude, shapes, and other sensible qualities, both of those which are and those which are not thus visible to the unaided sight. The instruments of this cla.s.s are designated by the general name of Telescope, and are of two kinds,--the refracting telescope, which derives its magnifying power from a system of convex lenses; and the reflecting telescope, which receives the image of the heavenly body upon a concave mirror.

2d. The second cla.s.s of instruments consists of those which are designed princ.i.p.ally to measure the angular distances of the heavenly bodies from each other, and their time of pa.s.sing the meridian. The transit instrument, the meridian circle, the mural circle, the heliometer, and the s.e.xtant, belong to this cla.s.s. The brilliant discoveries of astronomy are, for the most part, made with the first cla.s.s of instruments; its practical results wrought out by the second.

3d. The third cla.s.s contains the clock, with its subsidiary apparatus, for measuring the time and making its subdivisions with the greatest possible accuracy; indispensable auxiliary of all the instruments, by which the positions and motions of the heavenly bodies are observed, and measured, and recorded.

THE TELESCOPE.

The telescope may be likened to a wondrous cyclopean eye, endued with superhuman power, by which the astronomer extends the reach of his vision to the further heavens, and surveys galaxies and universes compared with which the solar system is but an atom floating in the air.

The transit may be compared to the measuring rod which he lays from planet to planet, and from star to star, to ascertain and mark off the heavenly s.p.a.ces, and transfer them to his note-book; the clock is that marvelous apparatus by which he equalizes and divides into nicely measured parts a portion of that unconceived infinity of duration, without beginning and without end, in which all existence floats as on a sh.o.r.eless and bottomless sea.

In the contrivance and the execution of these instruments, the utmost stretch of inventive skill and mechanical ingenuity has been put forth.

To such perfection have they been carried, that a single second of magnitude or s.p.a.ce is rendered a distinctly visible and appreciable quant.i.ty. "The arc of a circle," says Sir J. Hersch.e.l.l, "subtended by one second, is less than the 200,000th part of the radius, so that on a circle of six feet in diameter, it would occupy no greater linear extent than 1-5700 part of an inch, a quant.i.ty requiring a powerful microscope to be discerned at all."[A] The largest body in our system, the sun, whose real diameter is 882,000 miles, subtends, at a distance of 95,000,000 miles, but an angle of little more than 32; while so admirably are the best instruments constructed, that both in Europe and America a satellite of Neptune, an object of comparatively inconsiderable diameter, has been discovered at a distance of 2,850 millions of miles.

[Footnote A: _Outlines_, -- 131.]

UTILITY OF ASTRONOMICAL OBSERVATIONS.

The object of an observatory, erected and supplied with instruments of this admirable construction, and at proportionate expense, is, as I have already intimated, to provide for an accurate and systematic survey of the heavenly bodies, with a view to a more correct and extensive acquaintance with those already known, and as instrumental power and skill in using it increase, to the discovery of bodies. .h.i.therto invisible, and in both cla.s.ses to the determination of their distances, their relations to each other, and the laws which govern their movements.

Why should we wish to obtain this knowledge? What inducement is there to expend large sums of money in the erection of observatories, and in furnishing them with costly instruments, and in the support of the men of science employed in making, discussing, and recording, for successive generations, those minute observations of the heavenly bodies?