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in sketches C No. 3, and D No. 8, app i to this report. The harbor of North Edisto, to the south of Ch on, and that of Bull's bay, to the north, furnish safe refuges to ves finding themselves to leeward of Charleston entrance in bad we : On this account I have republished, with the present report, the tch of Bull's bay (E No. 6,) to accompany that of North Edisto, No. 7.) The comparison of the present shore line and channel of entrances to the Mississippi through the Northeast Pass, and the ass à l'Outre, with the survey made in 1839, is highly instructie, a I will be noticed more in detail in the hydrography of Section VIII. . The small number of harbors on the western coast, between San Francisco and Columbia river entrance, renders the contribution of the surveys of Trinity bay and Humboldt harbor of the greater relative importance. The charts of the western coast reconnaissance, in three sheets, were engraved, printed and published in twei.'y working days from the time the drawing was received at the office of the Coast Survey.

As the hydrography advances, tidal stations at important points are occupied, and continuous observations made. Self-registering tide gauges are constructing at the office, which will much facilitate the making of these observations. The results obtained in the Gulf of Mexico from the discussion of the tidal observations are of great interest, leading to the establishment of the laws by which the phenomena are regulated, and bringing within the reach of computation phenomena which were supposed by navigators to be due to the effect of the prevailing winds. Provision has been made for ex nding these observations during the coming season. I have placed in Ippendix to this report (Nos. 7 and 8) a paper read by me before. - erican Association for the Advancement of Science, on the tide: . . Cat island, in the Gulf of Mexico, and on a mode of representing the results of observations of tidal currents; (Sketches H, Nos. 2 to 6, inclusive.)

The observations for longitude, by astronomical observations, by the transportation of chronometers, and by telegraph, have been continued at various points; and notices will be found of them, in connexion with the several sections of the coast to which they belong. The discrepancy, which I have stated in previous reports, between the results of longitude by moon culminations and occultations, has been greatly reduced by the researches of Myers F. Longstreth, of Philadelphia; and the re-computation of our results, with his coefficients of the lunar theory, will be in the highest degree important. We expect, in this malier, to receive important aid from the Nautical Almanac office, under the direction of Lieutenant Charles H. Davis, United States navy.

An account of a second chronometer expedition between Liverpool and Cambridge is given in Section 1. At Cambridge, the transits are generally reduced by what has been called by Professor Airy the “American method," as having originated and been brought to its present advanced state in this country; Mr. Bond using an electrical clock and "spring governor,” of his invention, for marking the time at Harvard observatory. It is gratifying to national feeling to be able to state that the clock and governor made for the Coast Survey, by Professor Bond and his sons, has received one of the five honorary medals awarded by the commissioners of the late Industrial exhibition.

Charleston and Savannah, (see Section V.) Cambridge and Bangor, (see Section I.) have been connected for difference of longitude by telegraph, and our work has been joined in the same way with that of the British government in Nova Scotia.

Observations for declination of stars, giving irregular results for latitude, were made by Professor Mitchell, of Cincinnati, with the new declination apparatus of his invention, in 1849; and it is very desirable that they should be continued, with the apparatus as improved. This method has undergone the close scrutiny, and has received the approval, of the American Association for the Advancement of Science. A description by Professor Mitchell is given in the Appendix, No. 9.

The work of two more seasons will nearly, or quite, complete the determinations necessary for the appropriate length of the arc of the meridian passing down the Chesapeake, over the space where the measurement of Mason and Dixon was supposed by some to have indicated irregularities in the figure of the earth—while by others the measurement itself was rejected.

The telegraphic connexion between New Orleans and Washington for longitude will, it is expected, be completed next year, which will give the measurement of a portion of a parallel on the Gulf of Mexico, hereafter to be materially extended by the ordinary operations of the survey.

The examination of the Florida reef, made at my request, last winter, by Professor Agassiz, has developed, as was anticipated, the subject of its origin, growth, present character, and probable future progress, and in the most masterly manner. As it is desirable to give the results entire, in full detail, with drawings, and in an appropriate form, I have suggested that it be made a separate communication by the Treasury Department to Congress. In the mean time, I present from it a description of the topography of the keys and reef, which forms one of the chapters, with extracts from other portions of the report, in the Appendix, No. 10. The scientific details are so admirably interwoven with the body of the practical conclusions, that it has been found impossible to present portions of the o without injury to the whole.

One hundred and fifty-eight maps, charts, and preliminary sketches, are now in the hands of the draughtsmen and engravers, or have been published; a list of which is placed in Appendix No. 11, showing the number published, engraved, and in progress. Of these, the following have been engraved during the year to accompany this report, besides nineteen sketches of progress.

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9. Savannah city. ry, in conform 10. Savannah entrance. ct quoted abov 11. Bull's bay.

. which prelimin 12. North Edisto.

the objects prov 13. Florida peninsula.

eshuee excer 14. Cedar keys. 15. Preliminary chart of Key West. 16. Horn Island pass. 17. Delta of Mississippi. 18. Pass Christian. 19. Mobile bay. . 20. Five diagrams of tides at Cat island. 21. Mare Island straits. 22. Trinidad bay. 23. Humboldt bay. 24 to 26. McArthur's reconnaissance chart, 3 sheets. 27. Mouth of the Columbia.

II.-Sketches for location of light-houses, fc. 1. Holmes's Hole. 2. Beacon ranges, New York. 3. Fishing battery, Chesapeake. 4. Mosquito inlet. 5. Rebecca shoal. 6. Aransas pass. 7. Galveston bay. 8. San Diego. 9. Point Conception. 10. Point Pinos. 11. San Francisco entrance. 12. Humboldt bay. 13. Cape Hancock.

Hydrographic notices have been published by authority of the Treasury Department, and distributed within the past year, in relation to the following localities and subjects, important to the navigating interests of the country:

1. On the draught of vessels which can enter the south channel of the Columbia river, Oregon.

2. Sailing directions for entering the Columbia river as far as the harbor of Astoria.

3. Description of the islands and rivers between the harbor of Monterey and mouth of Columbia river.

4. Correction in the position of the Farallones and Point Lobos, entrance to San Francisco bay.

5. Information in relation to North Edisto harbor of refuge, South Carolina.

6. Information in relation to San Diego, Humboldt, and Trinidad harbors, western coast.

7. Extract from Lieutenant Commanding Alden's letter, in relation to Humboldt harbor and Trinidad bay.

8. Report of the latiti nah, (see Secti of Point Conception.

The list of geographi n connected for ’nded to this report (Appendix No. 12) contains the s been joined in ints of the coast survey determined up to July, 18 va Scotia. Usitions of a number of permanent objects determin 'ation of star plan, table. The list is accompanied by sketches

ions of the points referred to. A preface explains &

wivisions of the coast which are referred to; and, in a pol w way, the mode of determining the distances, latitudes, longitudes, and azimuths, which the table contains, their connexion through the figure of the earth, and their variation due to irregularities of figure and density. The degree of approximation which may be expected from the results of the computation, according to the stage of progress towards the final conclusions. is pointed out. The arrangement of the different parts of the table is also fully explained. Great care will be required in the revision of the printing of This iseful list; and even with it, errors must be expected, which, however, a subsequent impression will in a considerable degree correct.

The act of 3d of March, 1851, required an important class of duties of the Superintendent of the Coast Survey, namely: to provide for the examination of the sites of light-houses, beacons, buoys, &c., for, which appropriations were made, and which, in the opinion of the Fifth Auditor, required examination. .

"SEC. 2. And be it further enacted, That if such person as the Secretary of the Treasury shall designate shall report, in any of the cases herein provided for, that preliminary surveys are necessary to determine the site of a proposed light-house, or light-boat, beacon or buoy, or to ascertain more fully what the public exigency demands, the Secretary of the Treasury shall thereupon direct the Superintendent of the survey of the coast of the United States to perform such duty on the seaboard, and the colonel of the corps of topographical engineers to perform such duty on the northwestern lakes.

"Sec. 3. And be it further enacted, That the officer so directed shall forthwith enter upon the discharge of the duty; and, after fully ascertaming the fact: shall report: First, whether the proposed facility to - navigation is the nost suitable for the exigency which exists; and, second, where it should be placed if the interests of commerce demand it; third, if the thing proposed be not the most suitable, whether it is expedient to make any other kind of improvement; fourth, whether the proposed light has any connexion with other lights, and, if so, whether it cannot be so located as to subserve both the general and the local wants of trade and navigation; and, fifth, whether there be any, and if any, what other facts of importance touching the subject.

“Sec. 4. And be it further enacted, That all such reports shall, as speedily as may be, beluid before the Secretary of the Treasury; and if such as to authorize the work, without further legislation, he shall forthwith proceed with it, otherwise such reports shall be laid before Congress at the next ensuing session; but, in all cases when the person designated by the Secretary of the Treasury, under the second section of this act, does not report such preliminary examination as expedient, the provisions of this act shall, without delay, be carried into execu

tion."

The Secretary of the Treasury, in conformity with the first claure of the second section of the acť quoted above, called upon the Fi Auditor to report the cases in which preliminary surveys were nec sary to determine the sites of the objects provided for and enumera in the act. He reported that, with three exceptions, he had “no ko ledge of the reasons on which the several appropriations were and that “the necessity for the examination was apparent f many lights on the coast and lakes, and the fact that on some of the coast the lights are now so numerous that it is impossible istinguish one from another, and they are hence becoming a nuisa: (See Appendix No. 14, bis.)

In pursuance of the report of the Fifth Auditor, th m sury Department gave me instructions on the 29th of March lası, dix No. 13,) to proceed with the examination on the Atlantic coast, the Gulf of Mexico, and Pacific, including thirty-six localities from Maine to Texas, and on the western coast from Humboldt harbor, California, to the mouth of the Columbia river, Oregon.

Instructions, more or less detailed, were issued by me, as early as practicable, to the assistants of the coast survey operating in.or near These localities, directing surveys, reconnaissances, or examinations, as the cases required. Upon these reports the decision required by the law was made, and all the facts of the case communicated for the information of the department. These valuable reports of the assistants, usually accompanied by maps or sketches, or referring to the published maps of the coast survey, are embodied in the Appendix to the present report, under the heads of the different sections of the coast. The results are also briefly stated in the same connexion in the body of the report.

A detailed list of the subjects of my reports, in tabular form, is presented in the Appendix, (No. 15,) including the section of the survey in which the work was done; the name of the State, the special locality, the name of the object appropriated for, the officer by whom the examination was made, the date and nature of my reports. The table also contains the results of examination for sites of light-houses, &c., required under the act of Congress of the previous year, viz: those at Fort Point in the bay of San Francisco, at Point Conception, Point Pinos, near Monterey, Point Loma, near San Diego, California, and Cape Hancock or Disappointment, mouth of Columbia river.

T'he only objects remaining not reported upon are a light-house and fog-signal at Uiqua, in Oregon, and two on the coast of North Carolina, the sites for which are under examination, and upon which reports may soon be expected."

T'he examinations were made in eleven States, viz: Maine, Massachusetts, Rhode Island, Connecticut, New York, New Jersey, Maryland, North Carolina, Florida, Texas, California, and in Oregon Territory. And the objects reported upon are as follows: light-houses, eighteen; harbor or "bug” lights, three; beacons, six; light-boats, three; buoys, thirty-three; spindles, two; fog-bell, one; fog-whistles, four; floating bell-beacon, one. The special localities of these objects are given at length in the table, (Appendix No. 15,) and the details of the examinations are treated of under the heads of the different sections of the

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