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small vessels (though they might not hit the rock itself) which were thrown within its influence; while it prevents that rapid eddy, or return current, which formerly existed, and which threw all boats or “small craft” which once entered it into the very centre of the “Pot,” and then engulphed them.

The dangers to be apprehended from these causes (or if averted, encountering others in avoiding them) compelled all mariners to so direct their course through the Gate as to give the “Pot” as wide a berth as possible; and this wide steering again produced other difficulties equally attributable to it, but which otherwise could be easily avoided. Lieutenant Commanding Porter justly said that, “ Pot rock once removed, Hell Gate would be less dangerous by one-half, and the eddies, which are now the cause of half the difficulties, would in a

would be (Porter juster wise coulther difficua

Desure disappare now

The sketches which have been furnished of my examinations of Pot rock, during the progress of its demolition, have shown that it is at a mean depth of twenty feet at low water, one hundred and thirty feet in length, and thirty feet in average width. Before blasting, the least depth extended over a surface six feet square, while the average depth (vide Lieutenaut Porter's report) was about ten feet. With these facts before me, I have estimated that not less than (30,000) thirty thousand cubic feet of rock (hard gneiss) have been broken up, and scattered from the upper portions of the rock, by firing two hundred and twenly sub-marine charges, of one hundred and twenty-five pounds each, without drilling. This is equal to one hundred and thirty-five cubic feet of rock being removed at each blast; which calculation agrees remarkably well with the effect of each blast at Pot rock, and other points where I have examined for facts.

If it had required a pound of powder to a pound of rock, it would be a cheap process at Pot rock; for it is not easy to conceive how this very troublesome obstruction could have been so far demolished by any other mode than that used. The strength of the current is an effectual opponent to any drilling, even supposing it possible, by successfully anchoring a float, the position could be maintained. It was ably attempted and signally failed. The few moments at slack water are not sufficient to find the drilling point, and only sufficient for firing two or three charges, previously arranged for firing, without drilling.

In another part of the report of Lieutenant Commanding D. D. Porter, he states to you as follows: “There is a small, though very dangerous rock to the southward of Woolsey's bath-house. It extends about fifty yards out into the channel, and is connected with the shore-line at low water. There are three feet of water on it at high rides. On the first of the flood, a buoy, let go opposite ‘Gibbs's point,' (the southern approach to Hell Gate,) drifted round Hallett's point, between Pot rock and Way's reef, along the edge of the eddies, and over the above-mentioned rock, into · Pot cove. This happens to a great many vessels, and, but for this dangerous obstruction, they would drift into a safe harbor.”

I have now the pleasure to report that this rock, so well described by Lieutenant Porter, and so dangerous that I have seen two vessels bilge on it within a single hour, and still another rock, which, though

not mentioned by him, lies a few yards from it, and nearly as dangerous and destructive, have been entirely destroyed, annihilated by submarine explosions, without drilling, since the 7th of November, and there are now not less than seven feet water at low tide where they existed, or the usual depth of water on the shelving shore-line.

These two rocks have been, for all the past time, very destructive to vessels attempting to pass the south shore, or in anchoring near it, when they were covered, which was most of the time; and any vessel once in the Pot Eddy in a calm was almost certain to hit one or the other of them. Three schooners have bilged on them this autumn. They no longer exist, and, if nothing else had been done to improve Hell Gate, their destruction is worth ten times the amount of money expended by the citizens in this enterprize.

Should masters of vessels now desire to anchor near the bluff to the southward of Woolsey's bath-house, they can do so without the risk of having their keels or rudders knocked out by the current swinging them on those rocks.

They can be erased from your next edition of the chart of Hell Gate.

Cram's rock, or rather the rock which lies twenty-seren yards from the end of Cram's dock, with a clear channel between it and the dock, as also “Scaley rockand Shell rock,it is hoped, will be destroyed shortly, as they are always dangerous to vessels when the tide is above the half. The same can be said of the rock off“ Negro point,” “Baldheaded Billy,"* and “Blackwell's rock.”

Cram's rock is in area ten by fifteen feet and ten feet high, (or above the bottom,) and covered at high water.

A few hundreds of pounds of powder will remove them all, and their destruction will save hundreds of thousands of dollars to the coasting trade.

My experience at Hell Gate during the past four months has shown me, in a strong light, (and I desire particularly to call your attention to it,) the force of the remark in Lieutenant Commanding Porter's report, already referred to, where he says: “If any attempt is made to carry out the recommendations that have been frequently made relative to clearing away rocks in Hell Gate, I would suggest a close examination of the shore-line at low water. Many rocks will be found to exist of a dangerous character, and they have at different times done much damage to vessels of light draught.” He might have said, with equal propriety, that they are continually doing damage.

M. Maillefert has fired several discharges on the Frying-pan rock; but as the work is in progress, I shall not examine it till he closes for the season.

May's reef has also been the object of attack, as opportunity offered, and you have before you my careful examination of it in sections of three feet. As both these last-named dangers are in progress of removal, I shall not make further reference to them in this report. We have placed buoys at their extremities, which indicate their positions to navigators, and they are thus able to avoid them.

I must remark here that I have observed that, though most naviga

* Removed Dec. 4, 1851.

lors knew certain marks for aroiding these hidden dangers of the Gate, very few indeed of the many who pass the Gate have had any clear idea of their exact localities until they witnessed the operations there.

Referring again to the able reports of Lieutenants Davis and Porter, I can only add, that it appears strange, indeed, that this great national thoroughfare should have been so long neglected by the country; for I cannot hesitate to say, that it often happens that there are not less than two hundred sail of vessels and steamers passing, or attempting to pass, Hell Gate at the same time, and all in this narrow channel of less than three miles in length.

A small amount of money for labor and contingent expenses, or two officers and ten men, with "carte-blancheat a powder-mill, are all that are required to clear the navigation from Governor's island to Throg's neck; and there is no part of the navigable waters of the United States which requires it more.

The happy results of the operations in the Gate prove conclusively what was only speculation until attempted; and it is to be hoped that this good work will not stop for want of the trifling means to carry it on.

Numerous masters of the coasting trade have expressed to me their extreme gratification in the results already obtained; and, such is their anxiety to have it go on, that they would be willing to be taxed for every passage through the Gate if the dangers were removed.

The propriety of the work is too apparent, in the vastly growing commerce, by sail and steam, of this great city, to require any argument in its support. In conclusion, I beg leave to state, that to Eben Meriam, esq., is justly due the credit (and it is not a small matter) of interesting (by the aid of the reports in the coast survey office) the wealthy merchants of this city in this matter, and procuring from them the advances necessary for the experiment of this attempt at improvement in Hell Gate.

I deem it also proper to state, that M. Maillefert, the ingenious and enterprising operator in submarine blasting without drilling, exhibits the most ardent desire to serve the public to the utmost of his ability, preferring the credit of success in his novel mode of operation to any pecuniary benefit; and, notwithstanding all he has done, he will be a considerable loser in money, unless the benefits of his enterprise shall successfully appeal for his reimbursement.

I would remark, for your information, that the destruction of the two rocks, so troublesome on the south shore, was completed in less than one hour's time, and at an expense of less than one hundred dollars each.

I have received every possible assistance from Mr. Meriam and M. Maillefert, and their working force; and the free use of two metallic life and surf boats from Mr. Joseph Francis, for all my examinations under your instructions; and cannot close this report without adverting to the great advantage, and most decided economy, in the use of Mr Francis's metallic boats at all times and in all places.

His boats have been in constant use for months, on and around the rocks at Hell Gate, and are now in daily use, and perfect order, without the expenditure of one cent for repairs. No collision (by any exertion of their crews) with the rocks hurts them, and we have purposely placed them directly over the charges of 125 lbs. of powder, and blown them up with the concussion of the water, without the slighest injury. Respectfully submitted.

Your obedient servant,

WASH’N N. BARTLETT. Prof. A. D. BACHE,

Superintendent, Washington.

APPENDIX No. 57.

Report of the Superintendent of the Coast Survey to the Secretary of the

Treasury, upon an examination in reference to a light-house at Humboldt harbor, California, made by Lieutenant Commanding James Alden, United States navy, assistant in the coast survey.

Coast SURVEY OFFICE,

November 19, 1851. SIB: I have the honor to report, in conformity with the law approved March 3, 1851, and the instructions of the Treasury Department, that the examination of the necessity for a light-house at Humboldt harbor, California, has been made, and the following is the report of Lieut. Com. James Alden, United States navy, assistant in the coast survey, by whom the examination was made. A sketch of the recconnaissance is herewith enclosed.

"On the north spit I have marked the place where I think the lighthouse should be located. It is the nearest point to the entrance, and is, therefore, less liable to be obscured by fog; and, with a beacon further back, the two would form the best range to pass between the north and south breakers—not that it should be attempted in the night, unless under the most favorable circumstances. As Humboldt is rather out of the way of vessels passing up and down the coast, I have thought that a light of the second or third class would answer the purposes required at that point, and be sufficiently large for vessels bound in to maintain their position during the night.”

I concur with Lieut. Com. Alden in the recommendation of a light of the third order, with a beacon light in rear, to give a range.

The department will decide whether authority exists to put up the proposed beacon as well as the light-house; and if not, I would respectfully request that an appropriation for it may be asked.

The tower of the light-house should be about twenty feet high, and the beacon be so placed that it will be still visible when running on the range line. It should be constructed so as to be moved without difficulty in case of a change in the interior. Very respectfully, yours, &c.,

A. D. BACHE, Superintendent. Hon. Thos. CORWIN,

Secretary of the Treasury.

APPENDIX No. 57, bis.

Letter of the Superintendent of the Coast Survey to Hon. Joseph Grinnell,

of the Committee on Commerce, H. R., communicating a report of Lieut. Bartlett, U. S. N., assistant coast survey, on the importance of a lighthouse at Humboldt harbor.

Coast SURVEY OFFICE,

January 24, 1851. DEAR SIR: I herewith transmit, for the information of the Committee on Commerce, a report in relation to the importance of a light-house at Humboldt harbor, California, by Lieutenant Washington A. Bartlett, United States navy, assistant in the reconnaissance of the western coast.

Yours, respectfully,

A. D. BACHE,

Superintendent Coast Survey. Hon. Joseph GRINNELL,

of the Committee on Commerce.

WASHINGTON, January 24, 1851. Sir: For the information of the Committee on Commerce of the House of Representatives, on the importance of a light-house at Humboldt harbor, State of California, I have to state, that Humboldt harbor, although only discovered in April, 1850, is already a seaport of great commercial importance in the coasting trade on the western coast.

Humboldt harbor is an extensive sheet of water, of good depth, having an easily accessible entrance from the sea, of about one mile in width.

The bar, having three fathoms at low tide, is one and a half mile outside of the sand points which form the entrance to the harbor.

The sea-shore is low, the sea-side of the harbor being narrow sand points, but slightly elevated above the sea; and hence a light-house is of the first importance to point out the entrance and proper bearing for crossing the bar. Large settlements-Humboldt, Eureka, and Union Town-have already been established on Humboldt bay, whence a road of forty miles communicates with the rich and extensive gold region of the Trinity and Klamath rivers.

The valley, which is watered by the streams which flow into Humboldt bay, is of exceeding fertility, and densely timbered with valuable forest trees.

The steam propellers from San Francisco to Oregon touch at Humboldt, and, before a light-house can be built, there will be a semi-weekly line of steamers between San Francisco and Humboldt. The best position for the town can only be determined by a survey of the entrance. Very respectfully, your obedient servant,

WASHINGTON A. BARTLETT,

Lieutenant U. S. N., Assistant Coast Survey. Prof. A. D. BACHE,

Superintendent U. S. Coast Survey.

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