Memphis Harbor, Tenn. (230-232 L.).-(For references to description and previous history and present, see the current annual report of the Mississippi River Commission and Report Chief of Engineers, 1905, Supplement, p. 155.) See plate No. 7, herewith. The survey of last fall shows that the sand bar from the mouth of Wolf River to the foot of Court Street has receded from 50 to 150 feet and the slope of the cross section shows a scour of from 5 to 45 feet. This scour, however, has only removed previous fills and has not impaired the effectiveness of the revetment.

Walnut Bend, Ark. (281 R.).—(For reference to previous history and works see the current annual report of the Mississippi River Commission and Reports Chief of Engineers, 1908, part 3, p. 2724, and 1909, part 3, p. 2739.) For map showing general conditions and work done this year see plate No. 9, herewith. At the end of last season's work there was about 4,200 linear feet of revetment in place. The project for the season's work contemplated extending the upstream revetment to Whitehall Landing, a distance of about 2,400 feet, and from the lower end of the existing work downstream about 600 feet, and the repairs to a break in the existing work at range 15. The necessary plant reached Walnut Bend on August 19 and work was begun at once constructing mattresses. During the first part of the season no unusual difficulties were encountered. During the latter part of the season, however, rapid rises in the river gave considerable trouble on account of the flooding of the dead-men holes. The paving consists of the usual form of riprap, except 500 linear feet, which is concrete 4 inches thick, of 1 part Portland cement and 12 parts river sand and gravel, reenforced with wire mesh. The concrete was mixed with a Hains mixer, operated in connection with a derrick. This proved an economical although a rather slow method. All paving was carried up to the top bank. The revetment was finally completed on February 26 and the plant towed to Memphis. The season's work resulted in the extension of the revetment upstream to Whitehall Landing, a distance of 2,380 feet, and downstream 580 feet, and the repair of the break in the old work.

The following is a table of cost:

Channel mattress No. 7 (917 feet long by 254 feet wide, equaling 2,329

Cubic yards of stone per cord of brush and poles, 0.68.

Channel mattress No. 8 (1,480 feet long by 254 feet wide, equaling

Cubic yards of stone per cord of brush and poles, 0.59. Channel mattresses Nos. 9 and 10 (596 feet long by 250 feet wide, equaling 1,514 squares):

Cubic yards of stone per cord of brush and poles, 0.46.

Connecting mattresses Nos. 17, 18, 19, 20, 21, 22, 23, 24, 25, and 26

Cubic yards of stone per square, 1.28.

Cubic yards of stone per cord of brush and poles, 0.81. Grading bank (new work, 2,397 feet long by 100 feet wide, equaling 51,617 cubic yards; repair work, 300 feet long by 70 feet wide, equaling 6,268 cubic yards; total grading, 57,885 cubic yards):

Coal, 6,492 bushels___

Labor, subsistence, and supervision___

Cost per linear foot, $1.50 (new work).

Cost per cubic yard, $0.0696.

714. 12 3, 317.95 4,032. 07

Paving bank (new work, 1,897 feet by 101.8 feet, equaling 21,453 square yards; repair work, 3,772 square yards; total paving, 25,225 square yards):

Stone, 6,352 cubic yards_

Steamboat expense--

Labor, subsistence, supervision, etc---

$11, 545. 76 1,500.00 7, 516. 66

Cost per square yard, $0.8151.

Cost per linear foot, $9.22 (new work).

Cubic yards of stone per square yard, $0.25.

Paving bank (paving with concrete, 500 feet by 93.5 feet, equaling

20, 562. 42

441.70 765.90

48.18 245. 03

25.00 926. 75

2,452.56

Field cost per linear foot of bank protected__-. Value of material on hand at the close of the season's work to the credit of Walnut Bend:

Wire strand, etc---

38.58

2, 418. 64

Helena, Ark. (306 R.).—(For references to previous history see current annual report of the Mississippi River Commission and Reports Chief of Engineers, 1905, Supplement, p. 155, and 1909, p. 2742.) Plate No. 10,' herewith, shows present conditions. With the exception of a small sink in the revetment about 500 feet below the elevator the work is in good condition. It is intended to repair this fault this season.

Old Town Bend, Ark. (324 R.).—(For references and previous history and works see the current annual report of the Mississippi River Commission and Report Chief of Engineers, 1908, part 3. p. 2728, and report for 1909, part 3, p. 2743.) Plate No. 11,' herewith, shows location of work and present condition of the revetment. At the end of last season's work there was 7,255 linear feet of revetment in place and this season's project contemplated the extension of the revetment downstream to the sunken timber, a distance of about 1,700 feet.

The plant with which this work was done left Memphis September 7, 1910, When only a short distance below the fleet the tow went aground, but was floated and arrived at Old Town on September 12. The first work undertaken was to pave the bank along some of the past season's work in order to free the

1 Not printed.

barges for brush service and to enable the contractor to deliver a supply of brush. Mat construction was begun on September 30 and prosecuted as rapidly as possible. There were no unusual difficulties encountered during the progress of construction, although rapid rises in the river on two occasions interfered with its progress. The paving along the season's work was carried up to about the 20-foot stage on the Helena gauge, high enough to cover the sand strata and make it perfectly safe for the present at least. The mattress work was completed on December 24 and the mat plant towed to Hopefield Bend, Ark. A small party was left at Old Town to complete the paving, which was accomplished on January 14.

The season's work resulted in the extension of the revetment downstream 1,700 feet.

The following is a table of costs:

Channel mattress No. 9 (798 feet long by 250 feet wide, equaling

Cubic yards of stone per square, 0.84.

Cubic yards of stone per cord of brush and poles, 0.55.

Channel mat No. 10 (903 feet long by 250 feet wide, equaling 2,257.5 squares):

Cubic yards of stone per square, 0.808.

Cubic yards of stone per cord of brush and poles, 0.508.

Connecting mats Nos. 28 to 35, inclusive (573 squares):

Strand, -inch, 70 pounds___

Strand, f-inch, 3,395 pounds_-.

Strand, 1-inch, 6,054 pounds__

Wire, No. 12, 1,700 pounds_

Staples, 150 pounds..

1.98 60. 83 160.49 37.40

3. 15

Connecting mats Nos. 28 to 35, inclusive, etc.-Continued.

Clips, 4-inch, 36.

Clips, -inch, 650.

Brush and poles, 8,677 cords.

Stone, 520 cubic yards..

Steamboat expense

Labor, subsistence and supervision_.

Cost per square, $9.85.

Cords of brush and poles per square, 1.51.

Cubic yards of stone per square, 0.91.

Cubic yards of stone per cord of brush and poles, 0.60.

Connecting mat No. 27, 181 squares (repairs to old work):

Strand, 4-inch, 420 pounds__

Strand, -inch, 600 pounds___.

Strand, 4-inch, 1,680 pounds__

Wire, No. 12, 524 pounds_.

Staples, 50 pounds_.

Clips, 4-inch, 10.

Clips, -inch, 132.

Brush and poles, 280 cords_

Stone, 180 cubic yards_

Steamboat expense..

Labor, subsistence and supervision_.

Cost per square, $11.07.

Cords of brush and poles per square, 1.54.

Cubic yards of stone per square, 1.

Cubic yards of stone per cord of brush and poles, 0.65.

Paving (1909 work) (7,897 square yards):

Stone, 1,768 cubic yards____

Labor, subsistence and supervision_

Cost per square yard, $0.74.

$1.40 8. 19

1,214. 78

977. 08 380.00

2, 801.34

5, 646. 64

11.88

15. 24

46. 20

11. 53 1.05

.25

1.66

396.00

338.22

100.00

1, 082.00

2, 004. 03

3, 322. 07

2, 522.84

5, 844.91

It is impracticable to give the cost per linear foot on account of its being so scattered and detached.

Paving (1910 work) (2,149 linear feet, equaling 11,975 square yards):

Stone, 3,711 cubic yards_____

Labor, subsistence and supervision_--

Cost per square yard, $0.808.

Cost per linear foot, $4.50.

Cubic yards of stone per square yard of paving, 0.31.

Grading (2,149 linear feet, equaling 51,758 cubic yards):

Coal---

Labor, subsistence and supervision_.

Cost per linear foot, $1.89.

Cost per cubic yard, $0.0786.

Total field cost..

Office expense

Surveys -

Care of plant..

Repairs to plant-.

Depreciation of plant---

Total cost..

$6,054. 51 3,632.95

9, 687.46

570. 08 3, 501. 92

4, 072. 00

64, 956. 14 1, 190. 29

440. 16 1,069. 18 5, 102. 85 4,804.49

77, 563. 11