River in the vicinity of Council Bluffs, Iowa, the protection thus made practically becoming a continuation of the revetment constructed during May and June, 1890, and of similar make.

The work of procuring construction material was begun the latter part of July, but, owing to high water, actual work on revetment was not commenced until near the close of August. The revetment was started at A (see accompanying map), the terminus of the 1890 work, and extended down the left bank to B, a distance of 3,219 feet. On the reach B to C, a distance of about 2,800 feet, the work of protection was omitted, it being considered unnecessary owing to the unusually great resistance of the bank against erosion.

A comparison of the surveys made in 1879 and 1890 showed no perceptible change in the shore line between B and C, although the channel of the river followed that shore during the intervening time.

The revetment from C to F was built continuous, with the exception of a space D to E, 418 feet in length, extending above and below a gumbo point.

This projection was found to act as a dyke, with detrimental effect to the régime of the river, and consequently was left unprotected in anticipation of future erosions sufficient to wear it away and produce the desired shore line.

The manner of obtaining material and the method in which the revetment was constructed will be described under the several heads, as follows:

Cutting brush.-About 92 per cent of all the willow brush used was purchased standing in the field, and was cut, bound with wire, hauled to accessible landings, and loaded on barges by day labor.

The remaining 8 per cent was purchased delivered on the bank of the river, and thus the necessary labor was confined to loading the barges.

A brush-cutting party was organized on July 20, and, with an exception of eleven days in September, the force was employed continually until October 19. A second brush party was placed in the field August 10 and disbanded August 31. Measurement of the brush taken immediately after the barges were loaded was used in settlement for purchases made.

Most of the brush was obtained in the vicinity of Plattsmouth, Nebr., although a few barges were loaded near the mouth of Boyer Creek. All barges were loaded to carry from 175 to 225 cords of brush each, and, owing to the increase in density caused by thus heavily loading the barges, it is estimated that a gain of 20 per cent in the actual amount of brush was made over the measurement of previous years, when the barges were loaded to carry only 100 cords. The total amount of brush used during the season was 3,448 cords; and the average cost per cord, after being loaded on barges, was $1.956. It was found necessary to haul some of the brush 3 and 4 miles by teams, and in consequence the average cost of the brush was about 30 cents per cord greater than it was in 1890, when the distance of haul was less. Sinking piles.-Oak anchor piles, varying in length from 20 to 25 feet, were sunk 10 feet apart along the bank at the water's edge. Nine hundred and sixty piles were sunk, and the average penetration was 18 feet. The average cost of sinking each pile (exclusive of cost of material) was $1.186+, and the cost per foot of penetration was 6.6 cents.

The piles were purchased of S. P. McConnell, of Council Bluffs, Iowa, and were delivered at the boatyard for 15 cents per linear foot.

Mattress.-Mattress work was commenced on September 1 and finished October 25. From September 8 to October 20 a second mattress party was employed. The mattress was woven 1 foot thick and to an average width of 694 feet, and was strengthened with the usual longitudinal and tranverse -inch galvanized cables running through the mattress 10 feet apart. A 4-inch galvanized cable was used on the outside selvage edge.

Grading bank. The work of grading bank to a slope of 3 on 1 was done by using hydraulic graders Nos. 1 and 2, and the time occupied was from September 7 to October 31. A large portion of the material in the bank was hard gumbo, and the progress of the work was necessarily slow. The approximate amount of earth moved by the graders during the season was 45,775 cubic yards, and the average cost per cubic yard was 44 cents.

Rocking bank. The rock used was a limestone, quarried at Weeping Water, Nebr., and furnished on barges at Omaha by Van Court and Lemist for $1.1475 per cubic yard.

The required number of barges were loaded daily from September 9 to November 15. A rigid inspection as to the manner of loading resulted in obtaining 2,862 pounds per cubic yard as the average weight during the season.

The upper bank was rocked to a depth of 1 foot from the line of anchor piles to the standard high-water line on the slope, the average width being 27 feet.

Sinking mattress.-The mattress was sunk to the bottom of the river by the use of

about one-half cubic yard of rock per linear foot or 21 pounds per square foot of mattress.

Anchor cables.-The anchor piles were connected by -inch cables to deadmen sunk from the top of the high bank. The deadmen used were oak sticks, 6 to 8 inches in diameter and about 34 feet in length.

Towing. The brush and rock used during the season were transported by the use of the steamer Capitola Butt, she having been chartered for the work at a compensation of $20 per day.

During the first part of July the towboat was sent to St. Joseph, Mo., from which place she returned to Omaha with two hydraulic graders in tow. The total distance traveled by the towboat during the season of 137 days was 2,940 miles, and her average daily running expense, exclusive of the charter, was $33.01.

Repairing and launching plant.-The work upon repairs to plant which was begun the latter part of the fiscal year ending June 30, 1891, was continued to October 1. The hulls of pile-sinkers Nos. 3 and 4 and of the accompanying umbrella boats were wholly rebuilt above the water line.

All portions of quarter boats Nos. 2 and 4 below the second lower web strake were replaced by new material.

Extensive repairs were made to three 64-foot barges and to nine 100-foot barges. As the cost of repairs considerably exceeded the estimate, only such temporary repairs were made to the remainder of the boats as were thought necessary to warrant them standing the work for one season. Each boat was launched as soon as it was repaired and calked.

Pulling out boats.-Work of pulling out the boats on to the storage ways was commenced October 26 and was completed November 27.

Ice formed a gorge in the river on November 18, and eight boats were caught therein; but fortunately they were, with one exception, near the boatyard, and by the aid of the towboat the ice was broken about them sufficiently to admit of their being moved to the ways, where they were afterward pulled out.

The survey quarter boat was being used by a party at the time of the gorge, and was caught in the ice near the Northwestern Dikes. False ways were constructed, and the boat was pulled out at that place.

Care of plant.-On December 1 the boats and other engineer property were placed in charge of four watchmen, which number was reduced to three on April 15. On April 7 the survey quarter boat was launched from its winter quarters at the Northwestern Dikes and towed to the boatyard, where it has since been used for the accommodation of the watchmen. There being no construction work in operation, the remainder of the plant was left on the storage ways.

Surveys.-During the month of November a survey was made of the river from the mouth of Boyer Creek to the Union Pacific Railway Bridge. The computed distance between secondary triangulation stations Crescent and Flagstaff was taken as a

base line.

The shore lines of the Iowa and Florence lakes were located, and ties made to street corners at Florence, Council Bluffs, and Omaha. The notes were platted at the Omaha office during the month of January. A portion of the map was used to accompany a report submitted February 13 relative to any probable danger which might exist of a cut-off taking place through Florence Lake and East Omaha.

In order to note the rapid changes due to erosion, the right shore line of the river in the vicinity of Florence Lake was surveyed on May 23 and again on the 31st. The position of the shore line at the time of the last survey is shown on the accompanying map.

Cutting banks.-The most radical change due to erosion occurring on the Omaha reach during the year was in the right bank, in the vicinity of Florence Lake, where the cutting after April 1 was both constant and rapid. The maximum normal cut between X and Y (see accompanying map) from November to May 31 was 600 feet, and the area of ground washed away between the two points amounted to 47

acres.

Water flowed back and forth between the river and the lake during May and June, and the direction of flow changed as the elevation of the stage of the river was above or below 557 feet, Omaha gauge. Considerable cutting has taken place in the left bank from the mouth of Boyer Creek down to the point opposite to Florence, the estimated average normal cut being about 200 feet since November.

Condition of revetment.-The unexpected rise in the river which took place in May, together with the usual April and June rises, have given the revetment a severe test. An examination of the entire Council Bluffs revetment was made on June 25, and while the stage of the river was too high to note its exact condition, yet it was apparent that no serious damage had occurred.

FINANCIAL STATEMENT.

Distribution of expenditure incurred in constructing 9,220 linear feet of revetment.

Sundry expenses: (office and telephone rent, traveling expenses, station

7,262, 94

2,676.61 10, 131. 42 2,360. 20

15, 168, 23 1,987.61

796.20

25.35

281.55

1,315,39

Exhibit showing cost per linear foot of each branch of the work; also the ratio of cost of

each item to total cost.

The map and photographs accompanying this report are described as follows: First. Map of the Missouri River from mouth of Boyer Creek to Union Pacific Railway Bridge. Surveyed November, 1891.

Second. Photograph showing Council Bluffs revetment. View taken from Gumbo Point looking down stream.

Third. Photograph showing Council Bluffs revetment. one-half mile above boat-yard, looking down stream.

View taken from a point

I wish to acknowledge the valuable assistance rendered by Assistant Ed. Jones, who was in immediate charge of the work of construction.

I am, colonel, very respectfully, your obedient servant,

CHAS. F. POTTER,

Division Engineer.

APPENDIX C.

ANNUAL REPORT OF MR. S. WATERS FOX, DIVISION ENGINEER, 1892.

MISSOURI RIVER COMMISSION,
OFFICE OF DIVISION ENGINEER,
St. Joseph, Mo., June 30, 1892.

COLONEL: I have the honor to submit herewith a report of the operations under my charge on the St. Joseph division of the Missouri River during the fiscal year ending June 30, 1892. The following maps and photographs accompany the report,

viz:

First. Two photographic views of construction work in Belmont Bend.

Second. Map (tracing) of St. Joseph Reach, showing location and progress of improvement works as well as changes in shore lines.

Third. Sketch map (tracing) of Atchison Reach, showing the new shore alignment at the Doniphan cut-off.

IN THE VICINITY OF NEBRASKA CITY, NEBRASKA,

The general repairs to plant, begun during the previous fiscal year, were continued until August 14, at which time all the wooden hulls had been repaired and launched. The new boiler for the steamer Sabrina was not received until August 10; the necessary alterations and repairs were begun August 15. Besides some changes inside the hull, the forward skylight was lengthened to take in the chimney casing, and the entire roof aft of the wheelhouse was raised to the level of the roof of the old skylight; the port wheel flanges were reforged, bushed, and shrunk on the shaft; the pedestals were reënforced with chains to prevent a rocking movement of the engine frames. September 7, these repairs, although not finished, were sufficiently advanced for service; and as the steamer was urgently needed on the work she was put in commission on that day and left for St. Joseph with a tow, consisting of one rock barge, one mattress boat, and one small barge, the latter being loaded with coal.

As no further work was contemplated at Nebraska City during the season, the storage and launching ways with their supports were taken up and loaded on barges for transportation with the entire plant to St. Joseph. On September 11 the office there was closed, and Assistant Joseph C. Meredith, who had been in local charge of the work, was assigned a position in the field on the St. Joseph Reach. The few hulls there at that time awaiting transportation to St. Joseph Reach were left in care of two watchmen. The last of these was taken in tow by the Sabrina September 27, and the watchmen were discharged.

Cost exhibit of repairs to and launching of hulls at Nebraska City, Nebr., from July 1, 1891, to June 30, 1892.

A reconnoissance of the reach was made June 8, 1892. The island revetment was intact throughout its entire length.

The river in Copelands Bend has not changed materially; its flow on that date was concentrated against the bluff near the lower end of the bend; from that point a crossing was made to Nebraska City Island, the current impinging on the revetment at a point about midway between its upper and lower extremities. For a distance of about 500 feet from its upper end the revetment is in dead water, while a shore bar partially submerged at that stage makes out for quite a distance.

At lower stages the river has evidently hugged the right bank, making a false point at the lower end of Copelands; and under this action the shore line from the point to the bridge has receded, until now it is very close to the bluff all the way.