the day-night (nytchthemerum, for which we have no precise synonym in our language), with its primal alternation of waking and sleeping, of labor and rest, is a vital condition of the existence of such a creature as man. The revolution of the year, with its various incidents of summer and winter and seedtime and harvest, is not less involved in all our social, material and moral progress. It is true that at the poles and on the equator the effects of these revolutions are variously modified or wholly disappear, but, as the necessary consequence, human life is extinguished at the poles, and on the equator attains only a languid or feverish develop ment. Those latitudes only in which the great motions and cardinal positions of the earth exert a mean influence exhibit man in the harmonious expansion of his powers. The lunar period, which lies at the foundation of the month, is less vitally connected with human existence and development, but is proved by the experience of every age and race to be eminently conducive to the progress of civilization and culture. but in our ignorance of that harmony their practical adjustment to each other is a work of difficulty. The great embarrassment which attended the reformation of the calendar after the error of the Julian period had in the lapse of centuries reached ten (or rather twelve) days sufficiently illustrates this remark. It is most true that scientific difficulties did not form the chief obstacle. Having been proposed under the auspices of the Roman pontiff, the Protestant world for a century or more rejected the new style. It was in various places the subject of controversy, collision and bloodshed. It was not adopted in England till nearly two centuries after its introduction at Rome, and in the country of the Struves and the Pulkova equatorial they persist at the present day, for civil purposes, in adding eleven minutes and twelve seconds to the length of the tropical year. Connected with the use of astronomy in all determinations of time is its application to the purposes of history and chronology. The want of reliable historical eras has involved many portions of ancient history, But indispensable as are these heavenly especially Oriental history, in the greatest measures of time to our life and progress, confusion. Almost the only events in very and obvious as are the phenomena on which remote times of which the date can be ascerthey rest, yet, owing to the circumstance that tained with precision are those which can be in the economy of nature the day, the month referred to eclipses. Thus, the battle between and the year are not exactly commensurable, the Lydian and the Median armies narrated some of the most difficult questions in prac- by Herodotus is by the eclipse of the sun tical astronomy are those by which. an ac- supposed to have been predicted by Thales curate division of time applicable to the vari- ascertained to have happened on the 30th of ous uses of man is derived from the observa- September, 610 B. c. The delay of Nicias to tion of the heavenly bodies. I have no doubt embark from Sicily-a delay which proved that to the supreme Intelligence which cre- "a sentence of death to the Athenian army' ated and rules the universe there is a har-was caused by an eclipse of the moon on mony, hidden to us, in the numerical rela- the 27th of August, 413 B. C., and the date tion to each other of days, months and years, of Alexander's passage of the Tigris, before the mighty battle of Arbela, is determined by a similar eclipse of the moon on the 20th of September, 331 B. C. These dates are ascertained by modern astronomy with as much precision as if they had happened yesterday, and without its aid no event in profane Oriental history as ancient as the seventh century before our Saviour could be fixed within a generation. States and the determination of the boundaries of the country. I believe that till it was done by the federal government a uniform system of mathematical survey had never in any country been applied to an extensive territory. Large grants and sales of public land took place before the Revolution and in the interval between the peace and the adoption of the Constitution, but the limits of these grants and sales were ascertained by sensible objects-by trees, streams, rocks, hills-and by reference to adjacent portions of territory previously surveyed. The uncertainty of boundaries thus defined was a never-failing source of litigation. Large tracts of land in the Western country granted by Virginia under this old system of special and local survey were covered with conflicting claims, and the controversies to which they gave rise formed no small part of the business of the federal courts after their organization. But the adoption of the present land-system brought order out of chaos. The entire public domain is now scientifically sur The second great practical use of an astronomical observatory is connected with the science of geography. The first page of the history of our continent illustrates this connection. Profound meditation on the sphericity of the earth was one of the main reasons which led Columbus to undertake his momentous voyage, and his thorough acquaintance with the astronomical science of that day was, in his own judgment, what enabled him to overcome the almost innumerable obstacles which attended its prosecution. In return, I find that Copernicus in the very commencement of his immortal work appeals to the discovery of America as completing the demonstration of the sphe-veyed before it is offered for sale; it is laid ricity of the earth. Much of our knowledge of the figure, size, density and position of the earth as a member of the solar system is derived from this science, and it furnishes us the means of performing the most important operations of practical geography. Latitude and longitude, which lie at the basis of all, descriptive geography, are determined by observation. No map deserves the name on which the position of important points has not been astronomically determined. Some even of our most important political and administrative arrangements depend upon the co-operation of this science. Among these I may mention the land-system of the United off into ranges, townships, sections and smaller divisions with unerring accuracy, resting on the foundation of base and meridian lines; and I have been informed that under this system scarce a case of contested location and boundary has ever presented itself in court. The general land-office contains maps and plans in which every quarter-section of the public land is laid down with mathematical precision. The superficies of half a continent is thus transferred in miniature to the bureaus at Washington, while the local landoffices contain transcripts of these plans, copies of which are furnished to the individual purchaser. When we consider the tide of population annually flowing into the public domain and the immense importance of its efficient and economical administration, the utility of this application of astronomy will be duly estimated. I will here venture to repeat an anecdote which I heard lately from a son of the late Hon. Timothy Pickering. Mr. Octavius Pickering, on behalf of his father, had applied to Mr. David Putnam of Marietta to act as his legal adviser with respect to certain land-claims in the Virginia military district in the State of Ohio. Mr. Putnam declined the agency. He had had much to do with business of that kind, and found it beset with endless litigation. "I have never,' he adds, "succeeded but in a single case, and that was a location and survey made by General Washington before the Revolution, and I am not acquainted with any surveys, except those made by him, but what have been litigated." Astronomical observation furnishes by far the best means of defining the boundaries of states when the lines are of great length and run through unsettled countries. Natural indications like rivers and mountains, however distinct in appearance, are in practice subject to unavoidable error. By the treaty of 1783 a boundary was established between the United States and Great Britain depending partly on the course of rivers and upon the highlands dividing the waters which flow into the Atlantic Ocean from those which flow into the St. Lawrence. It took twenty years to find out which river was the true St. Croix. that being the starting-point. England then having made the extraordinary discovery that the Bay of Fundy is not a part of the Atlantic Ocean, forty years more were passed in the unsuccessful attempt to recreate the highlands which this strange doctrine had annihilated, and just as the two countries were on the verge of a war the controversy was settled by compromise. Had the boundary been accurately described by lines of latitude and longitude, no dispute could have arisen. No dispute arose as to the boundary between the United States and Spain and her successor, Mexico, where it runs through untrodden deserts and over pathless mountains along the forty-second degree of latitude. The identity of rivers may be disputed, as in the case of the St. Croix; the course of mountainchains is too broad for a dividing-line; the division of streams, as experience has shown, is uncertain; but a degree of latitude is written on the heavenly sphere, and nothing but an observation is required to read the record. A But the scientific element, like sharp instruments, must be handled with care. part of our boundary between the British provinces ran upon the forty-fifth degree of latitude, and about forty years ago an expensive fortress was commenced by the government of the United States at Rouse's Point, on Lake Champlain, on a spot intended to be just within our limits. When the line came to be more carefully surveyed, the fortress turned out to be on the wrong side: we had been building a fortification for our neighbor. But in the general compromises of the Treaty of Washington by the Webster and Ashburton treaty of the 9th of August, 1842, the fortress was left within our limits. Errors still more serious had nearly resulted a few years since in a war with Mexico. By the Treaty of Guadalupe Hidalgo, of the 2d. of February, 1848, the boun dary-line between the United States and that country was in part described by reference to the town of El Paso as laid down on a specified map of the United States, of which a copy was appended to the treaty. This boundary was to be surveyed and run by a joint commission of men of science. It soon appeared that errors of two or three degrees existed in the projection of the map. Its lines of latitude and longitude did not conform to the topography of the region; so that it was impossible to execute the text of the treaty. The famous Mesilla Valley was a part of the debatable ground, and the sum of ten millions of dollars paid to the Mexican government for that and for an additional strip of territory on the south-west was the smart-money which expiated the inaccuracy of the map-the necessary result, perhaps, of the want of good materials for its construction. Ten millions of dollars would have gone a good way to ward the expense of a national observatory, and of a map of the continent constructed with entire accuracy. It became my official duty in London a few years ago to apply to the British government for an authentic statement of their claim to jurisdiction over New Zealand. The official gazette of the 2d of October, 1840, was sent me from the foreign office as affording the desired information. This number of the gazette contained the proclamations issued by the lieutenant-governor of New Zealand "in pursuance of the instructions he had received from the marquess of Normanby, one of Her Majesty's principal secretaries of state," asserting the jurisdiction of his government over the islands of New Zealand, and declaring them to extend "from thirty-four degrees thirty minutes north to forty-seven degrees ten minutes south latitude." It is scarcely necessary to say that south latitude was intended in both instances. This error of sixty-nine degrees of latitude, which would have extended the claim of British jurisdiction over the whole breadth of the Pacific, had apparently escaped the notice of that government. It would be easy to multiply illustrations of the great practical importance of accurate scientific designations drawn from astronomical observation in various relations connected with boundaries, surveys and other geographical purposes; but I must hasten to a third important department, in which the services rendered by astronomy are equally conspicuous. I refer to commerce and navigation. It is chiefly owing to the results of astronomical observation that modern commerce has attained such a vast expansion, compared with that of the ancient world. I have already reminded you that accurate astronomical notions contributed materially to the conception in the mind of Columbus of his immortal enterprise, and to the practical success with which it was conducted. It was mainly his skill in the use of astronomical instruments, imperfect as they were, which enabled him, in spite of the bewildering variations of the compass, to find his way across the ocean. One of the first practical applications contemplated by Galileo of his discovery of the satellites of Jupiter was the use that might be made of them in ascertaining the longitude at sea. With the progress of the true system of the universe toward general adoption, this problem was the object of universal attention. It was the avowed object of the foundation of the observatory at Greenwich, | side-and it seems to me there never was an and no one subject has received more of the consideration of astronomers than those investigations of the lunar theory on which the requisite tables of the navigator are founded. The pathways of the ocean are marked out in the sky above; the eternal lights of the heavens are the only Pharos whose beams never fail, which no tempest can shake from its foundations. Within my recollection it was deemed a necessary qualification for the master and the mate of a merchant-ship, and even for a prime hand, to be able to work a lunar," as it was called. The improvements in the chronometer have in practice to a great extent superseded this laborious operation, but observation remains, and unquestionably will for ever remain, the only dependence for ascertaining the ship's time and deducing the longitude from comparison of that time with the chronometer. as in It may perhaps be thought that astronomical science is brought already to such a state of perfection that nothing more is to be desired, or at least that nothing more is attainable in reference to such practical applications as I have described. This, however, is an idea which generous minds will reject in this every other department of human knowledge. In astronomy, as in everything else, the discoveries already made, theoretical or practical, instead of exhausting the science or putting a limit to its advancement, do but furnish the means and instruments of further progress. I have no doubt we live on the verge of discoveries and inventions in every department as brilliant as any that have ever been made that there are new truths, new facts, ready to start into recognition on every age since the dawn of time when men ought to be less disposed to rest satisfied with the progress already made than the age in which we live; for there never was an age more distinguished for ingenious research, for novel result and bold generalization. That no further improvement is desirable in the means and methods of ascertaining the ship's place at sea, no one, I think, will from experience be disposed to assert. The last time I crossed the Atlantic I walked the quarter-deck with the officer in charge of the noble vessel on one occasion when we were driving along before a leading breeze and under a head of steam, beneath a starless sky, at midnight, at the rate, certainly, of ten or eleven miles an hour. There is something sublime, but approaching the terrible, in such a scene-the rayless gloom, the midnight chill, the awful swell of the deep, the dismal moan of the wind through the rigging, the all-but volcanic fires within the hold of the ship. I scarce know an occasion in ordinary life on which a reflecting mind feels more keenly its hopeless dependence on irrational forces beyond its own control. I asked my companion how nearly he could determine his ship's place at sea under favorable circumstances. "Theoretically," he answered, "I think, within a mile; practically and usually, within three or four.” My next question was, "How near do you think we may be to Cape Race?" that dangerous headland which pushes its iron-bound unlighted bastions from the shore of Newfoundland far into the Atlantic, first landfall to the homeward-bound American vessel.* * Since the voyage in question was made a lighthouse has been built on Cape Race. |