Imagens das páginas
PDF
ePub

mile from the mid-channel. The “capstan' was planted in 1849, for neaving off a vessel which had grounded in this channel.

“The point I have marked as · E. Range was formerly a Pilot's Range, and fifteen months since was about fifty yards from the beach in the channel way; it is now 340 metres from the beach.

“You will see from the above, that the point of St. Joseph has, for five years, been working rapidly out to the southward, and as it encroaches on the channel, the opposite point of Mustang island wears away with equal rapidity. All of the point of St. Joseph, from the * Old Range' to the spit at the Narrows, is a loose, sandy flat, which has been entirely formed since 1846, and on which vegetation has commenced. I found an unusual depth of water on the bar, nine and a half to ten feet, which may be accounted for by the strong and continued southeast winds of this season; ordinarily there are from seven to eight feet."

A temporary tidal station was established in connexion with the soundings about Galveston, and observations made additional to those at the regular station, which has been left in charge of an observer. The latter station was transferred from Bolivar Point, for greater convenience, to the city of Galveston.

Light-houses, buoys, fc.-Appropriations were made at the recent session of Congress for light-houses in Galveston bay, and preliminary surveys have been required for their location.

My report upon the subject, and that of Lieutenant Commanding Craven, who surveyed the sites proposed, will be found in Appendix No. 38.

I have recommended the erection of three light-houses, namely: on Clopper's bar, Red Fish bar, and Half Moon shoal--the two latter conditional upon the approval of some competent engineer, doubts being expressed by Lieutenant Commanding Craven as to the stability of the foundation. (See sketch I, No. 2, and sub-sketches.) That officer suggests, also, the necessity of a buoy off Dollar Point.

The reconnaissance of Aransas Pass indicates such frequent and rapid shifting of the bar and beach, that no light-house can be suitably placed with a prospect of permanence. The report of Lieutenant Commauding Craven (Appendix No. 39, and sketch I, No. 3,) giving details of the harbor and its changes, recommends a small light-vessel and buoys on the bar. In the same connexion, objections are strongly urged against the present location of the light-vessel at Galveston.

SECTIONS X AND XI.—THE COAST OF CALIFORNIA AND OREGON.

(Sketch I.)

In my last annual report, showing the progress of the work in California and Oregon up to October, 1850, the future course proposed for the survey of the western coast was stated as follows: “To determine the geographical positions of the prominent points, correcting existing charts by them and by intermediate reconnaissances, and using them as points in the final survey; to make such surveys of harbors and anchorages, of sounds, of bays, and of portions of the coast, as may be most immediately useful, taking up first the parts necessary for the establishment of light-houses, beacons, buoys, and other aids to naviga tion, using the methods of the Coast Survey, and establishing such permanent marks as will enable us to bring together these detached parts into a complete survey of the coast; to publish the successive approximations which we make, so that, whenever we have better materials than those already existing for charts, they may be given to the navigator, without waiting for the best results which we can produce. In this spirit, the reconnaissance of the coast now preparing for publication will be followed by a similar one south from Monterey; the sites for the light-houses provided for in California, now under examination, will be reported upon; the preliminary survey of Columbia river entrance, now reducing, will be published, and the examination carried up the river to Fort Vancouver, and up the Willamette; the portions of San Francisco bay, the surveys of which are required by the Engineer deartment and for light-house purposes, will be first taken up, to be folowed by a complete survey of that and of the adjacent bays, after less known portions of the coast have been embraced in the work.” In accordance with the principles thus laid down the survey has been prosecuted, upon a scale increasing as new appropriations became available, and with all the energy to be expected from the meritorious officers engaged in it. Although it was late in this season before the operations could be disembarrassed of difficulties growing out of the want of funds and the peculiar circumstances of the country, yet the beneficial effects of a more liberal expenditure are beginning to be realized; and I feel justified in pointing to the results, as a worthy and valuable contribution towards the knowledge of our Pacific coast and the safety of its navigation. If those results are not fully equal to our expectation, they have fallen short only through causes defying the control of man—I allude to the lamented death of him from whom we had received most, and from whom we hoped so much more; the wreck and necessary abandonment (on the coast of Patagonia) of our steamer; and the serious injury and detention of our sailing vessel south of San Francisco—disasters which have combined to leave our hydrography, especially, behind our hopes and just anticipations. fore proceeding to an account of the work, I feel that a pause is due to honor the memory of him who was its able and ardent pioneer, and whose name must hereafter be identified with the western coast as its most distinguished and useful explorer—Lieutenant Commanding Wm. P. McArthur, United States navy, assistant in the coast survey. The tribute paid by his associates to his memory seems to deserve a place in the records of the government and the work which he so faithfully served and honored; it is accordingly annexed in Appendix No. 40. I proceed to J. the state of the work. It will be remembered that, up to the date of my last annual report, our operations had furnished: 1st, a general sketch of the coast from Monterey to the Columbia river, with hydrographic notices, including detailed descriptions of rincipal entrances, and with a table of approximate longitudes and }. 2d, a preliminary survey of the Columbia river, from its entrance to a point above Astoria; 3d, a survey of Mare Island straits, in the bay of San Pablo, interior to that of San Francisco; and 4th, reports

apon light-houses for the bay of San Francisco, for Cape Disappointment, at the entrance of the Columbia river, and for New Dungenness and Cape Flattery, in Oregon.

Since then, the leading objects in our plan of operations have been the exact determination of the position of prominent points, and the surveys necessary for the establishment of lights and channel-marks most important to the present wants of navigation. The astronomical and topographical parties, and, as far as practicable, those engaged in triangulation and hydrography, have combined upon the same localities to effect the rapid completion of the purposes in view; and the two former parties have been for the most part left together, for convenience of co-operation and economy of transportation. The triangulation party has united with its normal scheme not only the surveys requisite for the location of light-houses, but those of a general character called for by the joint commission intrusted with the selection of sites for military and naval establishments. The hydrographic party, crippled in its operations by causes already cited, and which will be more fully dwelt upon, bas lent its aid to the others, and of late has been occupied in important independent examinations; among which the continuance of the general reconnaissance to the southward of Monterey ranks first, and will be pushed as rapidly as practicable. I proceed to state briefly, reserving details for their proper place, the general results of the season, which are:

1. The exact determination (for which see Appendix No. 41 bis) of Point Conception, the Hatteras of the western coast, and its survey for the location of a light-house. . The latitude was computed from astronomical observations made at that point; the longitude, from the comparison of observations there of moon culminations with others made on the Atlantic coast. The magnetic variation was also determined. The topography exhibits the proper site for the light-house authorized by Congress, and embraces several miles of the neighboring shore.

2. Similar observations to fix the geographical position of Point Pinos, at the entrance of Monterey; and a similar survey, indicating the best situation for a light-house. (See Appendix No 42.)

3. The astronomical observations made for determination of Punta Loma, in the bay of San Diego. The triangulation and topography of that bay, covering all that portion of it available for commerce; and so much of the hydrography as is necessary for the entrance, and with reference to location of a light-house. Also sailing directions for approach and entrance of the harbor; and a light-house report. (See Appendix No. 43.)

The topography embraces all that will be needed, after completion of the hydrography, for a harbor chart.

The triangulation extends from the False bay, on the north, to the Mexican line, on the south—thus connecting the coast survey work with the “initial point” of the boundary survey, established by Major Emory, United States topographical engineers. A sketch of the islands called “Los Coronados” has also been furnished, giving their approximate position.

4. Observations at the entrance of Columbia river for the position of Cape Disappointment, with a topographical survey of the cape, and a report for the location of a light-house, by law provided for, on that point. (See Appendix No. 44.)

The fogs prevalent upon this coast interpose a serious obstacle to observations for latitude, and to those for moon culminations; but the ordinary transit observations for time are more easily attained; and, to make these available, a chronometer expedition, between San Francisco and the mouth of Columbia river, has been organized, and is in progress, for the determination of longitude. Its results are not yet reported.

The topographical party has also extended its labors over Point Adams, on the opposite shore of the Columbia and its vicinity; and the hydrographical party has furnished views (eye-sketches) of the entrance and approaches of Columbia river, representing the features of the coast. Ten iron can-buoys were shipped in January, 1851, and the remaining two in February, to be delivered to the collector of customs at Astoria, Oregon. They have been received, and are to be placed under the direction of the coast survey party in the vicinity.

5. Preliminary surveys of Humboldt Harbor and Trinidad bay, the former believed to be, in point of excellence, the third harbor on that coast, easy of access, and having twenty-one feet on the bar at low water; the latter is reported as affording a good harbor of refuge, and, during half the year, a safe and convenient anchorage. A site for a hight-house, provided for by law, to be placed at ..". of these bay has been examined and reported upon. (See Appendix Nos. 57 an 57 bis.

6. §rs. in and about the bay of San Francisco, by combined triangulation and topographical parties, preliminary to the general triangulation, and yet immediately directed to light-house and defensive purposes. These embrace: .

A minute survey of Fort Point, at the entrance, and Alcatraz island, inside the bay; proposed sites for light-houses, (see Appendix No. 46.) The survey of the southern shore of the bay, founded on a measured base, and covering the ground pointed out by the joint commission for examination with reference to fortification. A reconnaissance of the Farallones (islands) for rectification of their position. A survey of Mare island, united with that of Mare island straits, and extended over the Straits of Carquines. This survey furnishes all the topography needed for the information of the joint commission, with a view to location at Mare island of a navy yard. Approximate determinations of latitude and longitude have been made on the southern shore of the bav.

#he more exact geodetic and hydrographic operations of the survey have been deferred in this harbor, (though their application at an early period is contemplated,) not through an under-estimate of its ultimate importance, but because existing charts yield better approximate knowledge of this than of other principal portions of the coast. It has therefore been estimated that the same amount of labor would yield greater and more immediately beneficial results even to the commerce of San Francisco itself, if dispersed through other fields, than if concentrated there. The charts of Captain Beechy, British navy, those of Captain Wilkes, of the United States Exploring Expedition, and, more recently, those published by Captain Ringgold, United States navy, leave far less to be desired for this than for other leading points.

7. To the above general account of operations it is to be added that the hydrographic operations have recently been directed to some revision of the general coast reconnaissance between San Francisco and Monterey; the extension of that reconnaissance from Monterey southward has been entered upon; and the survey of the bay of Monterey has been already executed.

Having received, during the last year, two interesting reports from Lieutenant W. A. Bartlett, United States navy, assistant in the coast survey, referring respectively to the general character of the coast of California and to the commerce of Columbia river, I have embodied those reports in the Appendix, (Nos. 48 and 49.)

Astronomical and magnetic observations.—Assistant George Davidson is in charge of these. At the date of my last annual report he was engaged at Point Conception, by far the most dangerous, and therefore the most important point, in reference to coast navigation. His observations were for latitude, for longitude by the method of moon culminations, and for magnetic variation and dip. The results have been computed and published.

From that point (after unavoidable delays arising from untoward circumstances, especially the injury of the schooner Ewing in a gale, which compelled the return of the party to San Francisco) assistant Davidson proceeded to establish an observatory near Monterey, in connexion with the survey for a light-house site—from thence to San Diego, and finally to Cape Disappointment, mouth of Columbia river ; pursuing the same system of observations at each as at Point Conception. The last advices left him at Cape Disappointment, whence he proposed to pass successively to the determination of Capes Orford and Mendocino, the two most prominent points between the Columbia river and San Francisco.

As soon as the advance of winter renders it necessary to leave the field in Oregon, assistant Davidson proposes to establish stations at points along the coast, and determine their differences of longitude by transit observations, in connexion with transportation of chronometers. The success of this scheme would add San Pedro, Santa Barbara, Trinidad and Humboldt bays to our list of points exactly determined.

Assistant Davidson is aided by Mr. John Rockwell.

Triangulation, fc., (sketch I, No. 9.)— Assistant R. D. Cutts was assigned to this section to take charge of a double party for combined purposes of triangulation and topography. The circumstances of the work pointed to his selection as peculiarly fitted for the superintendence of mixed operations, versed as he is by experience in every branch of the duties of the coast survey. His operations were specially directed to the examinations requisite for light-houses, and to those asked for by the joint commission on military and naval establishments, (for correspondence in relation to which, see Appendix No. 3, in my report of 1850.) The general surveys for the purpose last mentioned have been accomplished. The results for the season have furnished

1st. The survey of Alcatraz island and Fort Point, and a report on them as sites for light-houses. (Sketch I, No. 6, and Appendix No. 46.)

[graphic]
« AnteriorContinuar »