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3. “A beacon on Fawn bar, near Deer island, Boston harbor."

4. “ Two iron spindles on northeast ledge of the Graves and Harding's ledge, Boston harbor.”

5. “A light-boat off Brenton's reef, Narragansett bay.”

a. “ Eleven buoys in the channel to Commercial Point and Neponsett river, in Dorchester.”

A full report on this subject has been already laid before you in my letters of March 1, and February 22, 1851, copies of which I herewith enclose. It is only necessary to add that the buoys recommended have no other than local value.

b. “A light-house at the head of Holmes' Hole harbor.”

Further examination, which can be conveniently made during the approaching season, will better enable me to report on this point.

c. “A beacon on Fawn bar, near Deer island, Boston harbor."

d. "Two iron spindles on the northeast ledge of the Graves and Harding's ledge, Boston harbor."

The northeast ledge of the Graves and Harding's ledge, as the outposts of the obstructions strewing the approaches to Boston, should be conspicuously marked, and spindles surmounted by cones of different colors would answer this purpose. Harding's ledge especially, now a danger in itself, and but imperfectly marked by a buoy, if distinguished by a spindle, would serve a valuable auxiliary guide in the approaches to the main ship channel.

The northeast ledge of the Graves, similarly marked, would answer the same end with respect to the neighboring Hypocrite and the Broad Sound channels.

In connexion with the spindle on the northeast Graves ledge, a beacon on Fawn bar would be serviceable as a good intervening mark between that ledge and the Deer Island beacon. Vessels using the Broad Sound and Hypocrite channels would thus be guided by a succession of distinct marks, each becoming visible in its turn before the one passed is entirely lost.

The particular advantage of a beacon on Fawn bar would be the facility it would give to the navigation of the Broad Sound north channel; the buoy now moored on the bar, to further this end, could then be advantageously shifted to the narrowest part of that channel on the western side.

e. “A light-boat off Brenton's reef, Narragansett bay.”

The establishment of a light-boat here is of great importance. It would mark a dangerous shoal, and, in connexion with the Beaver Tail light, clearly define the entrance through the eastern channel into the harbor of Newport, Rhode Island.

I am of opinion that all the foregoing improvements would conduce largely to convenience and safety in the navigation of the respective waters where it is proposed to introduce them. Their value would be purely of a local kind, and they would have no other connexion with existing marks or lights than what has been pointed out. Respectfully,

C. H. McBLAIR,

Assistant Coast Surrey. Professor A. D. BACHE.

ter, it would stamination of the chaton, February 23, 2

Coast SURVEY OFFICE,

Washington, February 22, 1851. Dear Sir: From an examination of the chart showing the approaches to Dorchester, it would seem necessary for the safe navigation of those waters, which affects a large and increasing amount of tonnage, that eleven buoys, painted according to regulation, should be planted, viz: six to designate the channel to Commercial wharf, and the remaining five as guides to Neponset village. They must be distributed as follows: one on the west side of the channel opposite to Farm School, on Thompson's island, two on Cow Pasture bar, two on Term bar, and one opposite Commercial wharf.

The Neponset river would require one between Commercial wharf and Pine Neck, three along the curvature the river forms about Pine Neck, and one off the wharf at Neponset. Respectfully,

C. H. McBLAIR, Licut. Commanding U. S. N., Assistant Coast Survey. Prof. A. D. BACHE,

Superintendent Coast Survey.

Coast SURVEY OFFICE,

Washington, March 1, 1851. Sir: Lieut. Com. Charles Davis, to whom was referred my letter respecting the buoying of the channel near Dorchester, suggests that the outer buoys spoken of in that communication should be of the usual harbor size, while the inner ones, and especially the river buoys, might be much smaller and less expensive. I am, respectfully,

C. H. McBLAIR, Lieut. Com. U. S. N., Assistant U. S. Coast Survey. Prof. A. D. Bache,

Superintendent Coast Sarvey.

APPENDIX No. 23.

Report of the Superintendent of the Coast Suroey to the Sceretary of the

Treasury, on ranges in New York harbor; with extracts from the report of assistant J. B. Gl ck.

Coast SURVEY OFFice,

November 29, 1851. Sir : An examination made of Flynn's Knoll, New York harbor, with the members of the Light-house Board, induced a doubt in my mind whether the lighthouse proposed to be erected there was the best aid to navigation which could be suggested; and, indeed, whether it might not alter injuriously the present régime of the harbor. The inquiries of the Light-house Board were directed to the same points, and their conclusions will, therefore, also be before the department.

It occurred to me that a system of range-beacons could be used for passing Sandy Hook by the main ship channel, and for passing through the Swash channel, which would answer all the purposes of the proposed light on Flynn's Knoll, without being attended with any risk of causing new deposites on the bar, and which could be put up and maintained at a very small expense. I have accordingly caused minute surveys to be made of the shore near the probable sites of these beacons, and transmit, herewith, the sketches and report returned by assistant J. B. Glück, of the coast survey, and also a Coast Survey chart of New York bay and harbor, marking these and other sites on which range-lights may be established, to answer the purpose referred to above.

I would recommend two range-lights (beacon) to lead from the point G, in Gedney's channel, through the main ship channel, to the range of the beacons recommended in the sailing line H N through the Narrows; the beacons to be on the line G D or G M in the angle between them, as may be found most expedient, on an examination which should be made just previous to their location. The distance A D is rather small for the range, being less than one-ninth of G A. A beacon near L will furnish also other important ranges.

Also, two leading lights (beacon lights) for the Swash channel, nearly on the line S E. Before placing these lights the Swash channel should be carefully re-surveyed, which can be done at a very trifling expense by the Coast Survey, by using existing marks on the shore already determined in the survey, as there is an impression among the pilots that it is deepening. The beacons should be placed accordingly.

These lights should be so arranged that they will appear nearly in one when heading on the sailing lines They should be distant from each other not less than about one mile and a half, or one-sixth of the distance from which they are first required to give the range. They should be carefully screened, so as only to show a light on the range or ranges which they are to indicate ; and for distinction from each other, as they are only required to show some nine miles, the one near the Elm-tree beacon may be a red light, (deep red.) Yours, respectfully,

A. D. BACHE,

Superintendent United States Coast Survey. Hon. THOMAS CORWIN,

Secretary of the Treasury.

Extracts from a report on ranges in New York bay, to Superintendent, by

J. B. Glück, esq., assistant in coast survey.
UNITED STATES REVENUE Cutter Taney,

Brooklyn, New York, July 13, 1851. DEAR SIR: I have just returned from surveying the two ranges for entering Swash and main channels of New York bay, in accordance with your instructions of July 1.

The range for entering Swash channel, of which Elm-tree beacon forms one part, affords unusual facilities, as it strikes over the narrow brows of three elevations of one and a half, (13) one and three-quartets, (14) and two miles distance from the beacon; being, respectively, sixty, (60) eighty, (80) and one hundred and sixty, (160) feet high. That of sixty is bare ; that of eighty is covered with trees and thick brushwood from twenty to twenty-five feet high; and the one of one hundred and sixty with forest trees from sixty to seventy-five feet high. These three sites are upon the estate of Mr. George Ebbitt, New Dorp, Staten Island.

The range for coming through main ship channel touches the shore nearly a mile eastward of Point Comfort, through a very depressed part of the beach; the sand-banks on either side (from ten to twelve feet high) sinking nearly to the level of high-water mark. About three hundred metres back from the beach, the range strikes a swamp thickly covered with trees from fifteen to forty feet high ; from thence it runs mostly through woodlands-occasionally through settlements and clearings. About a mile inland from the beach, the range crosses the creek and marsh making into the westward of Point Comfort. Upon the whole line surveyed there is no point that reaches an elevation of twenty feet, and, as I am informed, there is none for five miles further back, to the hills near Middletown. From the terminus of my survey, I could see back nearly another mile, but no higher elevation on that extension could be gained ; I therefore confined the survey to the limits formed by the creek, on the banks of which the hills are slightly the highest. On this range both lights could be screened by trees, so as to be invisible to seaward, except on the range itself.

I am much indebted to Captain Rudolph, commanding United States revenue schooner Taney, and his officers, for their kindness in aiding the survey, and extending every facility possible for its accomplishment.

I send herewith the maps of New York bay, upon which I have marked the two ranges as directed.

The front light on Point Comfort range, for coming through main channel, might be placed at either A or B. The light would probably be sufficiently screened at A from being seen at sea, by the clump of trees about one hundred metres to the southeast, or by the woods on Sandy Hook, until the vessel is on the range itself. At B this purpose would be fully achieved.

The back light on this range might be properly placed at either C or D. The ground at D is several feet higher than at C, and therefore preferable. But little cutting is required to clear this whole range.

On the range for entering through Swash channel, where Elm-tree beacon now stands, will be the place for the front light. The breakwater should be moved to the west of the beacon instead of to the eastward, as this structure, in its present position, only serves to undermine the beacon, for the protection of which it was built. Complaints are made in regard to the color, which is red; at a distance of about two miles off shore I found it to be scarcely visible.

There are four points on this range where the back light might be

located, although C is, in my opinion, the most desirable site for it, being on an elevation of eighty feet, covered with trees and bushes, high enough to screen the light from either side. The sites A and B are bare, and, respectively, twenty and sixty feet high. That at D is from one hundred and forty to one hundred and sixty feet high. The thick and almost inaccessible forest makes it difficult to give a true delineation of the ground, or an accurate value of its elevation.

A black and white flag is fastened to the highest tree on the range, and the tree determined.

Trusting that I have executed this work to your satisfaction, I am, most respectfully, your obedient servant,

JOHN B. GLUCK,

Assistant in Coast Survey. Prof. A. D. BACHE, LL. D., Superintendent United States Coast Survey,

Mount Pleasant, Maine.

APPENDIX No. 24.

Letter of the Superintendent of the Coast Survey to the Secretary of the Trea

sury, recommending certain aids to navigation on the coast of New York and New Jersey, required by act of Congress and instructions of the

Treasury Department, and communicating the report of Lieutenants Commanding Jenkins and Woodhull, U. S. N., upon the same.

Coast SURVEY OFFICE,

June 13, 1851. SIR : In compliance with the act of Congress of March 3, 1851, and with the instructions of the department of April 2d, I have the honor to report on the buoys, beacons, fog-bell, and light-house, numbered 9, 11, 12, 13, 17, 18, in the tabular statement of light-houses, beacons, and buoys, for which appropriations were made in the act just referred to. A copy of the tabular statement is annexed, with the additional remarks now submitted. The details of the recommendations are given in the report of Lieutenants Commanding Jenkins and Woodhull, herewith submitted, and the localities are marked in the Coast Survey charts A, B', B2, C, D, and E, hereto appended.

No. 9. The buoy on Peafield reef, off Black Rock harbor, is recommended; also an additional buoy, for which, however, no appropriation has yet been made.

No. 11. The light-house on the north point of Gardiner's island is recommended, showing a red light. For the consideration inducing this recommendation, I refer to the report of Lieutenants Commanding Jenkins and Woodhull.

No. 12. The beacon in Sag harbor is recommended.

No. 13. The two beacons near Fort Hamilton are recommended. It is understood from the Chief Engineer, General Totten, that there will be no objection made to a temporary structure on the glacis of the redbubl of Fort Hamilton, in the locality marked on the chart.

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