The researches that were necessary to obtain the information required by law "for completing an accurate chart of every part of the coasts," have produced results of great economic and scientific value to the whole people, aside from their bearing on the interests of commerce and navigation; and which will contribute to the welfare of mankind long years after those who labored for them have passed away. A brief reference to a few of the many instances that might be cited to illustrate this perpetual influence to benefit our fellow men, may not be without interest to some of you present.
The application of the method of determining latitude by the measurement of small zenith distances, introduced by Captain Andrew Talcott of the Engineer Corps, U. S. A., while serving as an Assistant on the Survey, developed such radical errors in the star places given in the catalogues, that it led to an almost immediate call for better places, and arrangements were made with the observatories of the country to obtain the necessary observations, the Survey to pay for the labor involved. Stimulated by the knowledge that better work was required to meet the new demand, observatories deficient in instruments procured new ones, and soon furnished more accurate star places. Continued observation has added still further improvement until to-day we have catalogues that furnish the highest degree of precision. Professor Chauvenet defines "Talcott's method" as "one of the most valuable improvements in practical astronomy of recent years, surpassing all previous known methods (not excepting that of Bessel by prime vertical transits) both in simplicity and accuracy." But the advantages of the method have been found to be of a practical nature also; as it is productive of large economy in time and labor and has reduced the cost of the Survey many thousands of dollars.
The introduction of the Electric Telegraph was utilized by the Survey immediately on the practical accomplishment of the first line built, as a ready and improved means for determining longitude. Indeed, before Professor Morse had demonstrated to the world the truthfulness of his theories and experiments, the bare possibility of their success, and availability in the instant transmission of time, had been discussed on the Coast Survey, and the method to be first employed fully considered. But as in the application of all things under new conditions, experience is the teacher, and improvements were frequently made, until finally the invention and perfection of the "chronograph" has brought the method to a degree of precision that little more can be looked for. This method of determining longitude, introduced, fostered and perfected on the Coast Survey, has been more far reaching than geographical boundaries. All civilized nations have adopted it as the "American Method," and by the greater accuracy and reliability of the results the whole world has profited. The saving that has accrued by the more perfect determination of longitudes and the consequent increased safety to commerce, may be counted by millions every year; until one stands aghast in contemplation of the immensity of the sum, and fears to reckon it, even approximately, much less to prophecy what it may reach in the future. The system is but a natural sequence of the development of the telegraph, but emphasizes in a marked degree the spirit of progress that has ever been the active principle and guide in the conduct of the work, and advanced its methods to a state of perfection that has called forth the admiration of the scientific world.
The determination of the magnetic elements has been a subject of investigation from the early days of the survey; the knowledge sought was essential to the navigator, and in recent years, especially, has proved to be of the greatest practical value on shore. Limited by small appropriations the research was at first slow. But a trust fund left by Professor Bache, who always evinced the warmest interest in this particular investigation, added largely to the rapidity with which observations could be obtained, until now we have magnetic maps of the United States of such reasonable precision that they are authoritative, and are in almost daily demand. The results are more far reaching than their mere tabulation for the current year, as laws have been determined by which the declination in a locality can be ascertained for any year in the past.
There are but few places where the needle remains stationary, or points in the same direction, for any great length of time; it even changes daily and during the hours of a day; but the aggregate for a year will rarely exceed three or four minutes of arc. If we reflect then, upon the great use made of the compass in the settlement of the continent, and the proverbial neglect of the country surveyor of those days to record the local variation, or declination, with his work, we may see a little of the utility and practical purposes to which the results are constantly being applied. Property so little thought of a hundred years ago that a few acres more or less, lost or acquired, in its transfer defined by compass surveys, may suddenly assume a value in these days of progress that every square foot is worth dollars. When a dispute arises, deeds are examined, lost or obliterated marks are diligently sought for, perhaps one is found, surveyors are employed to run out the lines but only make the confusion worse. Instead of a few rods that were in doubt according to the best information, the surveyor's line makes it acres, and litigation looms up to eat the profits of the sudden rise, and there seems even then no satisfactory solution of the vexing problem. How valuable then must be the fact, that it is possible to compute the variation for years back, to the time the original survey was made, and furnish the deflection that will re-run the lines so clearly as to render the descriptions in the deed intelligible. This is but a single instance of the practical application of the knowledge gained; and if its general usefulness may be judged by the numerous inquiries made of the Bureau, it is not unreasonable to assume that time will bear increasing testimony of its great economic value from those who traverse the land, as well as those who sail on the waters.
The study of the recurrence of the tides along our extensive Coast lines, and determination of laws that would satisfy the great variance in the different periods, was a problem of no little magnitude but the greatest possible importance to our commerce. Much of the traffic along the coasts literally moves with the tides, and the cost of transportation is enhanced or diminished as the tide retards or advances it. Hundreds of dollars of expense may be incurred on a single cargo that must enter on the high water, but through imperfect knowledge of the master of the ship, is forced after sighting his port, to wait for the next tide, perhaps over night, and is driven to sea by a sudden storm and the voyage made several days longer. Such mishaps are not infrequent, and even at the great port of New York certain classes of vessels must "wait for the tide." The investigation of this complex subject has resulted in the acquirement of a knowledge that enables the prediction of the time of high and low water, and the height of the tidal wave, years in advance; and the mariner may now carry with him the tables published on the subject wherever he goes, and be independent of the doubtful communications he may otherwise receive from the shore. How many lives, how many dollars, have been saved by the knowledge gained?
But the investigation of the Tidal phenomena is of great scientific importance also; and a practical assistance in the great problems involved in the preservation and improvement of our harbors, but in this connection it probably falls more properly under the head of that greater study of the currents and their effects in the erosion, and building of the shores; the movement of the sands and formation of shoals and channels; termed "Physical Hydrography." Our commerce depends largely on this study for its perpetuation, for without harbors commerce must cease; and without harbors that will admit vessels of the largest class it must deteriorate. If commerce finds increased profits in large vessels it demands increased facilities, and the bars to the harbors with but six or eight feet of water on them a few years ago, must have ten, perhaps fifteen feet now, or the people must suffer their trade to pass to some more fortunate or energetic neighbor. This may be a hardship; but the demands of trade are inexorable, the profits must be reasonably assured, and those who would have the trade must comply with the requirements. Thus we see the striving for harbor improvements; the weakest making the greatest outcry that they shall not be left in the race. And the improvements must come in the end, or at least be attempted, for it is as much a law of commerce not to be hampered by small freights, as it is the law of nature that water flows down hill.
The outcry for "improvements" never grows weaker; it is the expression of a sincere conviction that the life of the community and the welfare of the "back country" depend upon its success for prosperity; it will not admit a rebuff and knows no such word as failure. Alleged authorities are consulted, a scheme of improvement is proposed and Congress is asked to vote the money, and finally the improvements are attempted. To be successful, the plan must conform to known general laws and the peculiarities of local conditions, many of which are only ascertainable by comparison of surveys at different periods. Theories advanced on data collected by one survey, may be strengthened or disproved by the facts ascertained in a subsequent survey; and it is only when the plan proposed meets the general laws and the local conditions at the same time, that it holds out promise of success. The study of the questions involved has been greatly aided by the work of the Coast Survey in improvements already attempted, and will be of greater assistance in the future. A positive knowledge of what the local conditions were when a harbor was at its greatest capacity, is of the greatest help in indicating the improvements necessary to restore it, after deterioration, or to maintain it in the full measure of its usefulness. Reliable charts do this, but they tell only half the story. A cause must be found for the effects that have been produced, and the remedy suggested must overcome that cause or control it, that it may work good instead of evil. In Physical Hydrography we learn the forces that nature has given us in the tides, the currents and the winds, and divert them from powers of destruction, as man in his ignorance may have led them, or in their warfare with one another they may have led themselves; and bring their mighty influence to protect, improve or maintain that which we originally had. Many harbors have suffered incalculable injury through the recklessness of these who live upon them, and whose daily bread is dependent upon their preservation; until the evil has become so great that commercial cities have now "Harbor Commissions," whose special function is the preservation and improvement of the harbors. The original surveys made by Coast Survey are the foundations on which they very generally must build, while re-surveys point out to them the obstacles that must be overcome. And thus it will ever be; and future generations endeavoring to meet the demands of commerce for increased facilities, will have still greater cause for thankfulness, that the wise men who inaugurated the work of the Coast Survey, determined that it should be executed with every improvement that science could devise; and that the able men who conducted it, did not yield to the clamor for quick returns and cheap results, of only momentary value. They will realize by the benefits they will derive from it, as do those now living who have watched its progress and development, that the best is the cheapest as it will be useful through all time.
In 1871 Congress authorized the execution of a Geodetic triangulation across the continent to connect the great primary triangulations along the Atlantic and Pacific coasts, and provided that the triangulation should determine positions in those States that made requisite provision for topographical and geological surveys of their own territories. Each year since then, a small sum has been expended on these works with gratifying results to the States that have availed themselves of the assistance. But it was not until 1878 that Congress designated the Bureau as the "Coast and Geodetic Survey," the official title it bears at this time. Many comments have been passed upon the action of Congress in extending the field of the survey to the interior in the establishment of a "Geodetic Survey," which has been looked upon as a purely scientific research for which the people had no immediate use, and could well afford to wait. But if the tree can be judged by its fruit, there will be no lack of testimony to the economic value of the Geodetic Survey in the near future; aside from its scientific and practical usefulness in perfecting the Survey of the Coasts. It will eventually be the basis for a precise survey of the whole country, determining boundaries, settling disputes, and furnishing incontrovertible data by which later generations can reproduce the marks placed by the local surveyors who make use of it, should they become obliterated or lost; thereby causing a direct increase in the security of property boundaries, and diminution in litigation that now costs millions of dollars annually. Some of the practical advantages to be derived from such a work, are now being demonstrated in Massachusetts in the "Town boundary Survey," as it is called, in which the corners, or turning points of the boundaries are being determined trigonometrically in a subsidiary work based upon the Geodetic triangulation of the Coast Survey. Each boundary corner in this scheme becomes a fixed point, and the direction and distance of many other corners are at once accurately ascertained in their true relations to it. The town boundaries will in due time be made the bases of reference for all local surveys and subdivisions of property; so that, eventually, there will be developed a cadastral map of unrivaled excellence, to supplement the Topographical map that has just been completed.
The imperfections of our "land surveys," brilliant as the scheme was conceived to be at the time of its inauguration, demonstrate only too clearly the extravagance of primitive methods in matters intended to be enduring. As time passes and property taken up under the "land survey" becomes more valuable, the difficulty of accurately identifying boundaries becomes more serious, until finally, it is only after long litigation that rights are determined. The inherent defect in the land survey to accomplish the purpose for which it was designed, lies in the fact, that while it parcels out the land, or a section of land, in a given number of lots, it fails to provide the means for identifying the boundaries of the lots at any future time; the marks placed for this purpose become obliterated or perhaps are moved by designing men, until a large area may be involved in great uncertainty. A triangulation covering the same ground and controlled by Geodetic work, determining the true positions of the old marks that may be left, would be the most economical and precise method of relieving these uncertainties and fixing for all time the location and boundaries of the lots originally parcelled out, by observations and marks that cannot be lost or obliterated.