REPORT ON THE COAST SURVEY

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Next to the triangulation, in the logical order of proceeding, but practically simultaneously with it as far as convenience will allow, it becomes necessary to determine, with mathematical precision, the latitude and longitude of the principal points of the survey; and the angles which the lines composing the system form with the meridian. This is an essential prerequisite to the subsequent projection of the whole in its proper place on the general map of the globular terrestrial surface, of which the several partial maps form a series of detached though successive portions.

TOPOGRAPHY.— The great primary triangulation having been established, the members of the system are afterwards subdivided into smaller triangles, called secondary; and these into others smaller still, called tertiary. By means of these, all the prominent points along the coast, and the principal features of its bays and harbors, are very accurately fixed. These form again points of departure, and checks to accuracy of the final survey in detail, of the minute configuration of the coast-line, and of the characteristics of the land, embraced within the limits of the work; including its superficial irregularities, its lithological character, the vegetable growth which covers it, and all natural objects or artificial constructions which are in any manner not worthy, or which affect its visible appearance. These operations are accomplished by a species of mathematical drawing conducted in the field, with the aid of an instrument called the Plane Table; and constitute the topographical portion of the survey.

HYDROGRAPHY.— All the laborious processes thus far described are confined to the land. Without them, the examination of the subaqueous irregularities, or the hydrographical survey, important as is this part of the work to mariners, could not be carried out so as to be of any substantial value. For it is the business of this branch of the survey to furnish an accurate delineation of he surface which the water conceals; and the positions of the remarkable points of this surface cannot be correctly placed on the chart, nor can the chart enable the navigator to recognize them, when he finds himself in their neighborhood, unless they are correctly determined in distance and direction from the objects visible on shore or above the water. The points, therefore, trigonometrically determined on the land, are used to fix the positions of sounding vessels, which are employed to ascertain the depth of the water and the nature of the bottom– the positions selected being so much the less distant from each other as the irregularities detected are greater, the shoals more dangerous, the submarine deposits more varied, and the seas under examination more frequented.

Observations upon the tides and currents, on the variation of the compass, and on the effects of winds upon the level of the water, furnish the remainder of the data necessary to complete the information which is to be presented on the chart– necessary, in other words, to form a graphic representation, which shall exhibit with minute accuracy the latitude and longitude of every remarkable point of the shore-line, and of every promontory, hill, mountain, or other object which, when the land is in view, can aid the mariner in identifying his position: which shall show, also, the situations and windings of channels; indicate the localities of hidden rocks and shoals; give the depth of the water, and the character of the bottom, everywhere within the limits which can be reached in ordinary soundings; and, finally, furnish all the information in relation to tides and currents, light-houses, beacons, fog-bells, buoys, and sailing lines, which is necessary to render navigation secure.

Such being the objects aimed at, and such the processes employed in conducting the difficult work of a Coast Survey, it seems proper, before proceeding to inquire how far these objects have been successfully pursued, or these processes skilfully and faithfully applied in the prosecution of the survey of our own coast, to review, in brief, the history of similar undertakings in other countries. To this topic, therefore, the committee propose to direct their next attention.

ACTION OF OTHER GOVERNMENTS IN REGARD TO SUCH SURVEYS

The national importance of works such as we are considering has for a long time been fully recognized by the governments of Europe. The French, who were the first to apply the principle of triangulation to the admeasurement of an arc of the meridian, with a view to determine the curvature and figure of the earth, were the first also to frame a territorial map upon the basis of geodetic surveys. The want of accuracy, however, in some of the elemental proceedings upon which this well-known map was founded, and the comparative meagreness of its details, gave rise to a scientific organization, inaugurated some fifty years ago under the auspices of La Place, for the purpose of its review and reconstruction. From that time to the present, the new geodetic survey of the kingdom, republic and empire has been steadily advancing; and, at the date of this report, about four-fifths of the work, embracing maps of some one hundred and seventy thousand square miles, may be regarded as nearly completed. The hydrography of the coast is finished. The cost of these magnificent contributions to the political importance and domestic interests of France cannot be estimated definitely; for the departments to which they have been confided have had other duties in charge; but the annual expenditure has been estimated at a little less than three hundred thousand dollars. The charts for general use are on a scale of rather more than three-quarters of an inch to the mile; some of them, intended to direct in the construction of public works, are on a scale four times larger.

The trigonometrical survey of England proper was begun in 1791, and will be finished in a few years more. A million of pounds sterling has been expended in its prosecution. The surveys have been made on a scale of two inches to the mile, with the exception of the six northern counties, where the scale was increased to six inches to the mile. The published charts are on a scale of one inch to the mile, and 108 sheets will cover the whole area of England and Wales.

The surveys of Scotland and Ireland are independent of that of England. They were begun later, and have advanced more rapidly; but they have been pursued into greater minuteness of detail, and have involved a greater rate of expenditure. In one of the documents laid before Parliament a few years ago (1851), the surveys of the three kingdoms were estimated to require, for completion, the sum of four millions one hundred and thirty-three thousand pounds sterling– a sum equal to more than twenty millions of dollars.

The Austrian Government has been, for some eighteen years, engaged in a survey of its dominions, at an annual cost of half a million of dollars. The Russian, the Prussian, the Swedish and Norwegian, the Sardinian, the Belgian and the Spanish Governments– indeed, all the governments of Europe, without a noticeable exception– have actively occupied themselves with the topography of their respective territories. A summary view of their labors, so far as definitely ascertainable at the latest dates, is exhibited in the following tabular arrangement:

Besides these, which, as the table shows, have produced more than eleven hundred sheets of finished map-work, there are the competed survey of Greece, and the surveys of Sweden, Denmark, Norway, Spain, and other countries, yet in progress.

In the course of these works, under the guidance of the ablest astronomers of their time,— La Place, Arago, Struve, Bessel, Schumacher, Gauss, Carlini, and their compeers,– the entire surface of Europe has been traversed, and a series of great arcs has been measured, extending together over nearly forty degrees. The chains of triangulation, which were constructed in the geodesy of each country, have been connected into one harmonious system; and it is not too much to say, that, in a very few years, every town and hamlet, and isolated villa– every mountain and hill, and lake and battlefield– will have its place assigned it, with mathematical precision, upon the general map of the European continent.

The hydrography of the coasts has been the object of equal care. Admiral Beechy, in his address before the Royal Geographical Society, in 1856, speaking of the hydrographic surveys of the north of Europe, which had been conducted by Russia, Prussia, Sweden and Denmark, says: “No fleet ever left England so well supplied with charts as the Baltic fleet of the last war.”

The survey of the East India Company’s possessions, under Colonel Lambton and Lieutenant-Colonel Everest, is distinguished among the geodetic achievements of the time, no less by its magnitude than by the skill and energy with which it has been prosecuted. It has measured, by great triangulations, a meridian arc of twenty degrees and twenty-one minutes, or of about fifteen hundred miles in length. Up to the present time, it has delineated four hundred and forty-seven thousand square miles of territory, being about one-third the whole area of India.

The hydrographic operations of the Company have embraced a part of the eastern coast of Africa, the Red sea, the Persian gulf, the Arabian sea, the Bay of Bengal, and the China sea. The charts, one hundred and forty-five in number, include the trace of a series of reconnaissances of all the shores, from the most eastern cape of Africa to China.

It would be out of place, in this very general review, to pursue into greater detail the history of these numerous and extensive and interesting foreign works; or to enumerate specifically the various and important benefits which they have been the means of bestowing upon mankind. If the committee have succeeded in showing that the governments of the civilized world have generally favored public works of the kind under consideration, their object will have been attained. But they believe that they have done more than this. They believe that enough has been said to make it manifest that all enlightened governments have vied with each other in the liberality, the zeal, and the perseverance with which they have prosecuted their several surveys; and have displayed, in the spirit which has sustained them, a most laudable ambition to secure fro their results the severest scientific accuracy.

FIRST ORGANIZATION OF THE COAST SURVEY OF THE UNITED STATES

It is believed that the honor of first suggesting a geodetic survey of the American coast, is due to the elder Professor Patterson, of Philadelphia; who, as early as the year 1806, availed himself of his intimacy with the President, Mr. Jefferson, and the gentlemen who formed his cabinet, to impress them wit the feasibility and policy of the measure. The act of Congress of 1807 was passed upon the executive recommendation. It authorized the President to cause a survey to be made of the coasts of the United States; in which were to be designated the islands, shoals, and places of anchorage within twenty leagues of the shore, with the courses and distances of capes and headlands, and such other matter as might be deemed proper for completing an accurate chart of every part of the coast. It also authorized the survey of St. George’s bank, and any other banks or shoals, and the soundings and currents beyond the limits aforesaid to the Gulf-stream.

A circular was accordingly issued by Mr. Gallatin, the able statesman then at the head of the Treasury Department, setting forth a project of a survey, and inviting to it the attention of scientific men. In this project, the proposed operations were distributed under three heads:

1. The ascertainment, by a series of astronomical operations, of the true positions of a few remarkable points on the coast.

2. A trigonometrical survey of the coast between these points.

3. A nautical survey of the shoals and soundings of the coast, of which the trigonometrical survey was to supply the basis.

Among the gentlemen who replied to the Secretary’s circular, was the late Mr. F.R. Hassler. This gentleman had, previously to this time, been engaged in the triangulation of the Swiss canton of Berne; and he proposed to place at the service of our government the ability and experience which he had acquired in the school of practice, for the execution of the American survey.

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