of other duties assigned to him in the same letter. By letter of Colonel J. H. Simpson, dated January 18, 1871, Mr. C. F. Trill was appointed as an assistant on this survey. On the 19th of January, 1871, Mr. C. F. Trill received complete instructions to proceed to Apalachicola, Florida, and inaugurate the work. On the 28th of the same month work was commenced by organizing a party, locating and arranging for the erection of platforms, taking soundings, and obtaining such information as might be of use in prosecution of the work. From this time work was pushed along as rapidly as the weather would permit. By letter from Colonel J. H. Simpson of the 20th of April, 1871, Captain A. N. Damrell was directed to turn over this work to Mr. C. F. Trill, leaving with him full instructions to insure the proper completion of the survey, and to return to Mobile, Alabama. At this time the examination and survey had been carried across the bar at the mouth of the river to 11 feet of water on the outer slope. A preliminary examination had been made for the purpose of locating the best channel to be improved across the Buckhead and other shoals in the eastern portion of St. George's Sound, to enable vessels to reach the city by the eastern pass, between St. George's Island and Dog Island. A preliminary examination had also been made to determine the practicability and propriety of improving New Inlet, which is a channel through St. George's Island, nearly south of Apalachicola, and almost in the prolongation of the natural channel across the bar at the mouth of the river. The survey was afterward conducted by Mr. C. F. Trill, till the 30th of June, 1871, at which time the field-work was completed as far as the funds available would allow. By the 1st of September, 1871, it is presumed that the field and office work will be completed, and a complete report, accompanied by maps and estimates, will be forwarded as soon thereafter as practicable. Amount allotted from appropriation of July 11, 1870.. Expended up to June 30, 1871, surplus being from funds transferred from Tombigbee River survey. $2,400 00 3,116 59 APPENDIX P 1. NEW YORK, May 13, 1871. GENERAL: I have the honor to transmit herewith the final report of my assistant, Captain William Ludlow, Corps of Engineers, and explanatory chart of the survey and examination of Charleston Harbor, provided for in section 2 of the act of Congress approved July 11, 1870. The two charts prepared by Captain Ludlow have been placed upon a single sheet in preparing the one now submitted, and some data, at points not covered by the recent examination, have been added from former surveys, in order to render, as far as practicable, a reference to other charts and sources of information unnecessary. The following recommendations, covering the expenditure of the money now available "for the improvement of the ship-channel in Charleston Harbor," and estimates for continuing the work, are respectfully submitted. Project for expending the $13,000 now available: 1. For the removal of the boiler of the iron-clad gunboat Palmetto State, sunk in the mouth of Town Creek to 12 feet, low-water soundings... 2. For the removal of the boilers of the two gunboats Chicora and Charleston, sunk off Marshall's wharf, Charleston... 3. For removing turret of monitor Patapsco, sunk near Fort Sumter to 15 feet, low-water soundings. 4. For the removal of the two wrecks, the Beatrice and companion, sunk in Beach Channel... Total...... $1,000 to $1,200 2,000 to 2, 400 1,000 to 1, 200 7,500 to 8, 500 11, 500 to 13, 300 5. Should the money more than suffice for the accomplishment of the work above named, the balance to be applied to dredging Beach Channel, using for this purpose the steamer and pump to be chartered for work on St. John's Bar, in case my project of the 9th instant, for operating on that bar, is sanctioned; otherwise balance to be applied, if sufficient 5 a. In removing wreck at Fort Sumter.... $1,000 to $1,200 I propose to invite proposals at once for executing the foregoing project. ESTIMATES. For continuing and, so far as our information now indicates, for completing the improvement of the ship-channels in Charleston Harbor, the appropriation of the several amounts below named is recommended, viz: 1. For removal of wreck near Fort Sumter.. 2. For removal of wreck of monitor Weehawken, sunk in 4. For dredging Beach Channel to a depth of 15 feet, and a width of 275 feet, low-water soundings. 5. For removing 125 lineal feet from the end of Bowman $1,200 00 12,000 00 10, 000 00 10, 000 00 8, 000 00 20, 000 00 Total to be appropriated.. 61, 200 00 Should the proposed removal of 125 feet from the end of Bowman Jettee be executed with such results as to suggest a further reduction in the length of that work, an additional appropriation will be requested. Very respectfully, your obedient servant, Q. A. GILLMORE, Major of Engineers, Brevet Major General. Brigadier General A. A. HUMPHREYS, Chief of Engineers, U. S. A., Washington, D. C. P. S.-As the removal of the turret of the monitor Patapsco secures 15 feet of water over the wreck, I have included it in the project for expending the existing appropriation, and have placed the cost of removing the hull the last on the list of estimates, for which appropriations are recommended. Should it be deemed necessary to reduce the estimates, this item ($20,000) may be omitted, making the total amount to be appropriated $41,200. Q. A. GILLMORE, Major Engineers, Brevet Major General. CAPTAIN: NEW YORK, October 20, 1870. In addition to these current observations, you are charged with "the examination or survey of Charleston Harbor, South Carolina," provided for in section 2 of the act of Congress making appropriations for rivers and harbors for the fiscal year ending June 30, 1870, for which the sum of $3,000 has been allotted. This must cover all expenses for field-work, office-work, and instruments. I suggest that yon assume personal charge of this survey, confiding the current observations to your assistants. The "examination or survey" should take note of and cover all important changes in the water-channels used for commerce, that have occurred since the last survey made by the Coast Survey in 1866. Particular care should be taken in reporting upon the location and character of obstructions in the channels, such as wrecks, in order that intelligent recommendations may be made concerning the propriety and cost of their removal. Charleston, South Carolina, April 20, 1871. MAJOR: I have the honer to submit the following report on the survey and examination of Charleston Harbor, made in accordance with your instructions of October 20, 1870. The large chart shows the field-work done, on a scale of 1,250 feet to the inch, or 15; and the tracing gives a scale of 500 feet to the inch, or, 6000, the hydrography of the Beach Channel. Inasmuch as the survey had for its object to ascertain by what means the harbor and its channels of entry might be improved, no time was lost in verifying the minor details of the Coast Survey chart; the instrumental work being at once directed to the point suggesting the possibility of improvement, the various wrecks in the harbor claiming consideration most readily, and a study of the harbor, and the records of previous examinations directing attention immediately to the Beach Channel. The position of the wrecks have been carefully determined, as well as those of the buoys and beacons; in the majority of instances correcting these as given on the Coast Survey chart, while, for the detail of the shore-lines, the chart has been followed. It was thought a matter of interest, in connection with a consideration of the régime of the harbor, to ascertain if any effect had been produced upon the curves of depth by Forts Ripley and Sumter, and soundings were accordingly made upon the middle ground surrounding Fort Ripley, and along the edge of the James Island Bank, from Fort Johnson to Sumter, thence in the direction of Cumming's Point. No change of consequence is apparent on the middle ground; in fact, there is a remarkable resemblance between the two outlines of the shoal. On the James Island bank, however, it is evident that Fort Sumter has exerted a positive though not as yet a very important influence on the outline of the bank. It appears that above Sumter the 3-fathom curve has been pushed back toward James Island, while east of the fort the curve has encroached considerably upon the deep water. In connection must be considered the fact, which the chart does not show, that in the vicinity of Sumter, and above it, the bank itself has been upheaved to a very considerable extent. The rationale, then, would seem to be that the fort, acting as a solid bulk-head, resists the incessant denudating action of the ebb-tide, and checks its flow over the shoal, and thus allows the bank to rise in height from increments deposited by the flood, at the same time the ebb is compelled to follow more the channel-line, and so act with in creased pressure against the shore of James Island Bank, cutting it away somewhat,, while, from being deflected over toward Sullivan's Island, (with a powerful influence on the beach channel) it allows the 3-fathom curve beyond the fort to gradually increase its distance to the east, until the two curves again meet off Cumming's Point. In this effect is not seen anything that can act unfavorably upon the channel-way, but merely a circumstance worth noting from its influence on the Beach Channel. The soundings made upon the bar of the Pumpkin Hill Channel are undoubtedly in excess of the actual average depth. This is owing to the fact that for nearly a month preceding the time when the soundings were taken the wind, blowing from easterly directions, had maintained more than average depth of water upon the bar. I have given the soundings as they appear in the field-book, since they do not bear upon any recommendation made in this report; but to show the average mean low-water depth, about 18 inches should be deducted from each sounding. The detailed report of the wrecks is given as follows, commencing with those furthest up the harbor. 1st. The Palmetto State.-This was an iron-clad gun-boat of southern construction, sunk in the mouth of Town Creek, just above the city, in 1865; it has been blasted by wreckers, working under a contract with the Treasury Department, and the machinery taken out. There are 12 feet of water over the decks, but only 6 feet over the boilers. Though not an important obstruction, it has caused disaster, and should be removed by blasting out the boiler to a depth of 12 feet at low water. To effect this would cost about $1,000. 2d. The Chicora and the Charleston.-These two wrecks have the same history as the Palmetto State, and lie nearly together in the Cooper river, below Drum Island, off Marshall's wharf. They have both been operated upon by wreckers, but the boilers remain as obstructions to vessels coming into the wharf. Over the wrecks themselves is as much water as near them, but the boilers are but 24 feet below the surface at low water, and they should be removed. The cost is estimated at about $1,000 apiece, $2.000. 3d. The wrecks near the entrance to Hog Island Channel are unimportant.-They probably aid in maintaining the reef or shoal which connects them with Shute's Folly Island, and may have a favorable influence in deflecting some of the flow from the Cooper River toward the city, which would otherwise escape by the Hog Island Channel. 4th. The wreck on James Island Bank consists of a boiler and other iron, but is entirely out of the channel, and does not require attention. 5th. The wreck near Fort Sumter consists of a boiler, &c.; and although no obstruction to commerce, should be removed for the reason that it deflects the tide from the head of the wharf at Sumter, thereby gradually shoaling the water. It will be cheaper to remove the wreck now than to extend the wharf hereafter. Probable cost, $1,000. 6th. The Patapsco was a single-turreted monitor, sunk in the channel-way near Fort Sumter. It has been heavily blasted. The decks over the engine-room blown off, although the engines are still in her. The pilot-house has been removed. The turret is inclined at an angle of about 35 to the west. There is now 15 feet of water over the wreck, except on the turret, the upper corner of which is but 5 feet below the surface. The great force of the current here renders the wreck the most difficult of all to work upon. To remove it entirely would be the proper method of dealing with it, and from the best opinion I can form, the cost to obtain 20 feet of water would be about $20,000. To blast off the turret, so as to have 15 feet over the wreck, would cost, say $1,000. 7th. The Weehawken was a single-turreted monitor, sunk off Morris Island, in a nearly east and west position, directly across the channel. It has been heavily blasted, and there are now 114 feet of water over everything. The engines have been taken out. The turret, of 12-inch iron, was blasted to pieces with an interior charge of 475 pounds of powder. The pilot-house, of 10-inch iron, was burst with two charges, one, underneath, of 475 pounds, the other, inside, of 250 pounds. The pieces of both lie in the hold of the vessel with the boilers. The sand has banked up on both sides of the wreck, except at the stern, which lies to the west, where the bottom has cut out for a distance of 40 feet, and the stern has broken off and fallen, holding to the remainder of the wreck by the lower parts. The wreck should be, as nearly as possible, removed. The esti mated cost is $12,000. 8th. The Keokuk was a double-turreted monitor, and lies in 15 feet of water, near the south end of Morris Island. It has 11 feet of water over it, and 1 foot on the turret. It lies entirely out of the path of any vessel, except a stray coaster bound south from Charleston; and even they can only in smooth water approach it, owing to its proximity to nearly constant breakers. From the same cause the wreckers have not disturbed it. To remove the wreck to a depth of 15 feet would cost $20,000. 9th. The Housatonic was a woollen vessel, blown up at anchor by a torpedo-boat, which sunk with her. The wrecks of the two lie nearly four miles due east of the Weehawken light-ship, in 44 fathoms of water. It is given in the margin of the chart. The wreck has been blasted, the stern blown off, and portions of the machinery taken out. Two boilers are still in her, weighing 40 and 50 tons each. From the quarter forward the ribs stand up to their full height, giving about 7 feet at low water. The wooden sheathing inside, and the planking outside, are eaten by worms down to the copper. It is a dangerous wreck, lying in deep water, in the track of northerly-bound vessels, and should be removed. The estimated cost to obtain 20 feet of water, is $10,000. All these amounts are, as nearly as possible, estimated for the actual cost of removal, and if contracts are made, the contractor is supposed to look for his profit to the value of the material raised. 10th. The wreck of the Raccoon lies upon the north breaker of the north channel, aud is no obstruction. 11th. The wrecks in the Beach Channel remain to be considered. These have been referred to in my preliminary report of January 27, 1871. They consist of the Beatrice and her companion, on Drunken Dick Shoal, and the Minho, Stono, and Prince Albert, on and near the end of Bowman Jettee. The position of these wrecks protects them from heavy seas in all directions, and they are almost constantly in comparatively smooth water; and in the event of a storm, the wrecking-boat can easily seek protection by passing round the jettee into the harbor. The water near them is not very deep, nor is the flow of the tide through the Beach Channel as rapid as in other points of the harbor. I am, therefore, inclined to believe that the amounts originally estimated for them would suffice for their removal; but this point has been already covered by your recommendation of an appropriation. The conclusions arrived at, as to the direction to be given to efforts to improve the harbor, do not vary from those suggested in my preliminary report. The channels now generally used, viz, the Pumpkin Hill, for all large vessels, and the Swash, for smaller ones bound north, are, in all probability, absolutely incapable of permanent improvement except at some vast expense. Their exposed position, the shifting, uncertain nature of the fine sand composing their bars, the prevalence of northeast, southeast, and southwest winds, whose fury is fully exercised upon them, the consequent changes, sometimes sudden, in depth and direction, all seem to discourage attempts to discover an effective plan of improvement. Dredging with some form of rotary pump of great power, and with improved appliances, might, by constant work, maintain upon these bars an increased depth of water. Notwithstanding that the expense of this would be great, and its efficiency uncertain, it might be advisable to make the attempt, were it only to ascertain what relation the cost would bear to the value of increased commerce and immunity from disaster, and at least have a basis of calculation and comparison. But, fortunately, there is found in the Beach Channel a direct opportunity of making a permanent improvement, and, by a comparitively small expenditure, give at once a channel of entry which shall be safe, convenient, and commodious. The permanent nature of this channel is proved by the various surveys made from time to time, which always give it in the same position, while the other channels have shifted continually. It has, at the present time, a depth of water greater than the Pumpkin Hill Channel, is sheltered in all directions from heavy seas until a safe depth is reached, is easy of access from the ocean, cuts off some 15 miles in distance for vessels in the northerly coasting trade, and would undoubtedly be used by all vessels bound north, were it not for the wrecks that obstruct it, and possibly some apprehension of the lumps at the inner mouth and the close approach of the Drunken Dick Shoal to the Bowman Jettee. The yellow curve in the small tracing shows those portions in the channel where the depth is 15 feet or more. It will be seen that a clear 15 feet can be carried through, except at two points near the inner mouth, where the curves approach to about 100 yards. Dredging on these two bars, and removing the 11-foot lump at the end of the jettee to a depth of 15 feet, would open the channel straight through. To effect both these objects, it is estimated, would cost about $10,000, putting the cost of dredging at $1 per cubic yard. There is one other recommendation made in my preliminary report for the improvement of the Beach Channel, to which it is again necessary to refer, viz, the removal of a portion of the Bowman Jettee. I am constrained to believe that this is required to render the Beach Channel all that its proper régime would make it, for reasons that may be given, as follows: At the time the jettee was built, the sea had encroached upon the shores of Sullivan's Island, had attacked and partially undermined the walls of Fort Moultrie, and threatened, by making a breach across the island, through the low place east of the fort, to imperil its existence. The jettee was built, and at once its favorable action was evinced. The high-water mark rapidly receded from Fort Moultrie; the whole line of the beach advanced against the ocean, and the smaller jettees and sea-wall supported the Bowman Jettee, repulsed the attack of the sea, and allayed the apprehensions felt for the safety of the island. Another effect, this time an unexpected one, was discovered. The jettee had been built to connect the Drunken Dick Shoal with the shore, and so close what, (at that time, from the incessant washing of the sea into it,) was not a channel, but a slue-way of uncertain depth and no importance. But when |