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R9.

SURVEY FOR LOCATING THE TERMINUS OF THE FORT ST. PHILIP CANAL

UNDER THE LEE OF SABLE ISLAND.

This survey was projected on the following suppositions:

1st. That a sheltered harbor excavated under the lee of Sable Island with a breakwater located on the shoal ground to the northward, if practicable, would be preferable as an entrance to the projected canal, to an entrance projected from the front of Sable Island directly into the throat of Breton Island Pass.

2d. That by inclosing Grand Bay a tidal reservoir might be estab. lished, receiving and discharging through the entrance to such harbor and thus creating currents sufficiently powerful in scouring effect to maintain the depth of entrance given to the harbor.

3d. It was assumed that this direction given the entrance would necessitate artificial works interfering the least with the flow of tidal currents through Breton Island Pass; that protection of the west end of Breton Island would be perhaps rendered unnecessary, and that a breakwater on the shoal between the east and west forks of Breton Island Pass, while protecting the entrance to the harbor from the north, might be so planned as to deepen and lengthen the west (or harbor) fork.

4th. It appeared evident that the entrance, so located, could be better protected by fortification on Sable Island than it located at any other point.

The survey of 1871 and 1872 gave all the data for considering this location, excepte

1st. Borings and soundings along the line of probable location of the trunk of canal.

2d. For inclosure of Grand Bay.

These data are now presented in the following report and on the chart herewith:

UNITED STATES ENGINEER OFFICE,

New Orleans, La., May 25, 1874, Sir: I have to make the following report on the "survey for locating the terminus of the Fort St. Philip Canal under the les of Sable Island.” The survey was commenced March 19, 1874, and the field-work was finished April 22, 1874.

The triangulation, soundings, level-line, and sections of borings, have been plotted on a single sheet, which is submitted herewith.

A tide-gauge was established at Camp Howell, in Mississippi River, and another near station 6, in Grand Bay. A level-line has beeu run from Camp Howell to station 2, and from station 2 to the tide-gange in Grand Bay. Taking high-water of 1874 as the plane of reference, we have plotted the section of the proposed route so as to show low-water in Mississippi River, 1872. Its reference is 6.45 feet.

Extreme high-water in Grand Bay, for time covered by survey, 2.13 feet.
Mean low-water in Grand Bay, for same period, 5.40 feet.
Extreme low-water in Grand Bay, for same period, 7.03 feet.
In order to preserve the record of this work tive bench-marks have been established.

Bench-mark No. 1 is the top of a stake at the northwest corner of the house at Camp Howell. It is 0'.66 below the zero of the gauge at Camp Howell, and its reference is 0'.76.

Bench-mark No. 2 is the top of a piece of 1-inch round iron, driven into the end of a yellow-pine stick, 3' by 12" by 12'', buried in the ground and standing upright near the northeast corner of house at Camp Howell. It is 4'.85 from the northeast corner of the house, and 15'.45 from northwest corner of the house. This bench-mark is 1'.03 below the zero of the tide-gauge at Camp Howell, and its 'reference is 1'.13.

Bench-mark No.3 is the head of a g-inch by 16-inch iron bolt, driven into the end of a cotton-wood log, 3 feet long, buried in the ground, standing upright, near the southeast corner of the bonse, at Camp Howell. It is 6'.05 froin this corner and 16'.05 from the southwest corner of the same bonse. This bench-mark is 1.03 below the zero of the tide-gauge at Camp Howell, and its reference is 1'.93.

Bench-mark No. 4 is a stake 82'.5 from station 6, in the direction of station 2, (see

chart.) The top of the stake is 2.36 below the zero of gauge in Grand Bay. Its reference is 3.99.

Bench-mark No.5 is the head of a f-inch by 16-inch iron bolt, driven into the end of a cotton-wood log, 3' by 15", buried in the ground, standing upright, 49' from station 21, in the direction of station 2. This bench-inark is 2'.49 below the zero of the gauge in Grand Bay, and its reference is 4'.12.

Seven borings have been made, 4 to a depth of 100', 1 to 97', 1 to 79', and 1 to 44. The sections of the different strata are shown on the vext sheet.

The specimens, 56 in number, are properly numbered for each boring, and the depth from which the earth was taken is indicated on each specimen. The location of each boring is indicated on the chart.

A hydrographic survey has been made of Grand Bay. This work can be added to our general chart by reducing the scale to yodou.

I have estimated the amount of excavation for the proposed route (a 2, to A 8, see chart) from the end of the lift-lock to 27 feet water in the Gulf,

Width of canal at bottom, 200 feet; depth at extreme low-water, 25 feet; depth at mean low-water, 27 feet, (26.63.) Side slopes 1.

The outer end of the canal to be 1,000 feet wide for a distance of 8,075 feet. Total excavation in cubic yards, 10,203,915. I have also estimated for the breakwater and jetty, indioated on the general chart.

Breakwater: Breakwater to have a section similar to the construction at Rotterdam, length 11,600 feet.

Depth at east end, 21 feet.
Depth at west end, 14 feet.
Width at top, east end, 30 feet.
Width at top, west end, 20 feet.
Cubic yards, fascines and ballast, 368,479.
Cost, at $5 per cubio yard, $18,423.95.

Jetty:
Length, 11,100 feet.
Depth at outer end, 11 feet.
Cubic yards, fascines, and ballast, 87,704 feet.
Cost, at $5 per cubic yard, $438,520.

Sections of the bayous, on the south side of California and Grand Bays, have been made as directed by you.

Each section is lettered, and the corresponding letter on the general chart indicates the approximate location of the section. Very respectfully, your obedient servant,

H. M. ADAMS,

Lieutenant of Engineers. Capt. C. W. HOWELL,

Corps of Engineers, U.S. A. The work is located in the collection-district of New Orleans, near Fort St. Philip, La., and the nearest light-house is that at the head of the passes.

R 10.

SURVEY OF THE NECHES AND ANGELINA RIVERS, TEXAS, MADE IN COMPLIANCE WITH SECOND SECTION OF ACT OF JUNE 10, 1872.

UNITED STATES ENGINEER OFFICE,

New Orleans, Lo., December 30, 1873. GENERAL: I have the honor to forward herewith report on survey of the Neches and Angelina Rivers.

The recommendations made by Lieut. H. M. Adams meet my approval.

The charts to accompany this report were forwarded to the Chief of Engineers, September 29, 1873; five sheets. Very respectfully, your obedient servant,

C. W. HOWELL,

Captain of Engineers. Brig. Gen. A. A. HUMPHREYS,

Chief of Engineers, U. S. A.

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Report of Lieut. H. M. Adams, Corps of Engineers.

UNITED STATES ENGINEER OFFICE,

New Orleans, La., November 22, 1873. Sir: I have to make the following report on the survey of the Ange. lina and Neches Rivers, Texas:

THE ANGELINA RIVER.

This survey was commenced November 9, 1872, and the field-work was finished December 21, 1872. The Angelina is a tributary of the Neches. Our survey was extended from the junction of the two rivers to Platonia, one hundred and four miles. This river is only navigable during high-water, which lasts but a small part of the year. The principal product of the country drained by the Angelina is cotton, and much of it finds its way to market by the great northern railroad before the annual rise in the river, which makes the stream navigable. A few trips are made up the river each year by the steamboats Laura and Graham, the only boats now engaged in this trade.

For a complete description of the river and of the obstructions to navigation, reference is made to the report of Mr. A. De Man, which is appended, marked “B.” With this report are submitted two charts, giv. ing the plan and numerous cross-sections of the river. No recommenda. tion is made for the improvement of the Angelina, because no improvement seems to be required.

THE NECHES RIVER.

Our field work was commenced December 25, 1872, and finished April 2, 1873. The survey extended from the mouth of the river to Boonville, one hundred and ninety-five and one-half miles. The Neches is navigable, at all stages of water, to a point known as Weiss Bluff, fiftyone miles from the mouth. The river above Weiss Bluff is only navigable during high-water.

There are, at present, three steamboats-Stonewall, Laura, and Graham-engaged in the navigation of the Neches; a large amount of lumber is annually shipped by sailing vessels from the Lower Neches to Sabine Pass and Galveston. The principal obstruction to the navigation of the river is the bar at its mouth in Sabine Lake. The depth of water on this bar is 3 feet at low-tide, and the distance across the bar from 5 feet depth on one side to 5 feet 'depth on the other side, is 6,850 feet. The bar is composed of fine sand and mud, and is formed by the deposit from the river-water.

The following estimate is submitted for excavating a channel across the bar in a straight line, from A to B, (see chart No. 3,) 80 feet wide and 5 feet deep.

Cubic yards of excavation, 47,851.
Cost, at 50 cents....
Add 10 per cent. for contingencies...

$23, 925 50

2, 392 55

Total ...

26, 318 0

Statistics showing the amount of trade at Sabine Pass have been col. lected. This information is appended, and marked "A," of the imports and exports; about one-third of the amounts stated belong to the. Neches Rirer trade.

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