means are clearly impracticable, and where the only alternative is that or no navigation at all. I do not pretend to say that dredging alone would bring the Illinois to that condition which it is entitled to, nor that an attempt should be made to perfect its navigation to the proposed standard in a few years time, but after another two months' walk afoot along its banks, I am more than ever convinced that, dredging, with its indispensable accessories-catch basins for the sediment-bearing tributaries and longitudinal dikes, where ever found advisable, would gradually, as the requirements of commerce advance, deepen and regulate its channel to the full satisfaction of all demands that ever will be made upon it.

Respectfully submitted.

Brevet Major General J. H. WILSON,

H. A. ULFFERS, Civil Engineer, Assistant.

Lieutenant Colonel U. S. A., Keokuk, Iowa.

APPENDIX J.

UNITED STATES ENGINEER OFFICE,

No. 23 Rampart Street, New Orleans, July 7, 1869.

GENERAL: In compliance with the requirements of circular, dated Headquarters Corps of Engineers, June 10, 1868, I have the honor to submit the following annual report of progress made in all works of river and harbor improvements and surveys under my charge, for the fiscal year ending June 30, 1869:

1. Survey of Galveston Harbor, Texas, with a view to forming plans for its improvement and preservation.

This work was completed and full report made by Brevet Brigadier General M. D. McAlester, on the 9th of June, 1868. There is yet remaining of the appropriation made for carrying on the survey the sum of $25 92, now in my hands, which amount is no longer needed on this work, and may be returned to the general appropriation from which it was taken.

2. Improvement of the mouth of the Mississippi River.

The last annual report rendered by Brevet Brigadier General M. D. McAlester, major of engineers, in charge of the work, gave a detailed account of the construction and working to the date of July 1, 1868, of the steam dredge-boat Essayons, especially designed by General McAlester, and built under his direction for this work.

The Essayons was at that date just out of Hampton Roads, bound for this port, and yet in the hands of her contractors. She arrived at New Orleans July 16, and was immediately placed in dock to repair damage sustained during her voyage, and to make such alterations of her machinery as the experience gained by her trip suggested.

The voyage from Boston to New Orleans disclosed several minor defects in the construction of her machinery, but proved her to be, with the latter in good working order, a reliable, seaworthy vessel.

All such repairs and alterations deemed advisable, as by the terms of their contract devolved on them, were made by her contractors, in whose hands she remained until the 6th of August, at which date she was formally turned over to the United States.

The time intervening between the 6th of August and the 3d of

September was consumed in making such further alterations from the original plan as did not properly devolve on the contractors.

On the 3d of September, the vessel sailed for Pass à Loutre, (previously selected for improvement,) but, owing to a series of accidents, (mainly due to the inexperience of the assistant steam engineers, who were not well acquainted with the working of the peculiar machinery of the vessel,) only one and one-half hour's work on the bar was done during the month, the remainder of the time being spent in making repairs.

Lieutenant D. W. Payne, Corps of Engineers, United States Army, during this time was in active superintendence of the work, under the orders of General McAlester. I extract from his report to me, dated July 2, 1869, to show the progress made in October and November, 1868:

"In October, the depth of water in the channel was increased from twelve feet six inches to fourteen feet. The vessel worked nine days and seven hours during the month. She was prevented from working the remainder of the time by bad weather and by accidents to her machinery. Two blades of the forward screws were broken off on the 1st, by striking a log while running down the river. On the 14th, the two remaining blades were broken off by striking something hard in the channel. From the 14th to the 30th, work was continued with the after scraper. On the 30th, the vessel was taken to New Orleans to repair the forward screw, and did not return to Pass à Loutre until the 19th of November, by which time the channel had filled so as to give only eleven feet six inches of water on the bar.”

During November, only one and one-half day's work was performed. The depth of water on the crest of the bar was increased to thirteen feet.

On the 25th of November, the Essayons was ordered to New Orleans, preparatory to a transfer from General McAlester to Colonel F. E. Prime, and was detained until the 8th of December.

Only one day's work was done at the mouth of the river in December, and that resulted in breaking two blades of the forward screw, after which the vessel was again brought to New Orleans for repairs. These repairs, owing to delay in receiving the new blades required, detained the vessel in New Orleans until the 3d of February, 1869. During this long detention the reversing gear of the engine, which had given much trouble, was put in good working order.

The Essayons returned to Pass à Loutre on the 3d of February, 1869. Lieutenant Payne reports for the remainder of the fiscal year as follows: "On the 4th of February, but eleven feet six inches of water was formed on the crest of the bar at Pass à Loutre. Eleven and one-fifth days' work were done by the Essayons during February. She was prevented from working during the remainder of the month by thick fogs, taking in coal, and making repairs. Two blades of the forward screw were broken off on the 9th. The depth of water over the bar was increased from eleven feet six inches to fourteen feet.

"In March, six and one-half days' work were performed, and by it the depth of channel increased to fifteen feet. Operations were very much hindered by fogs. On the 29th, another blade of the forward screw was broken, leaving but one for service, and in consequence the vessel was again taken to New Orleans for repair of screw, and did not return to Pass à Loutre until the 20th of April. During her absence, the channel filled to fourteen feet six inches.

"During April, after her return to Pass à Loutre, the Essayons was

prevented by thick and continuous fogs from working but one and onehalf days. On the 28th, one blade was broken off the forward screw. "In May, the depth of water was increased to seventeen feet four inches by fifteen and one-half days' work; the remainder of the month was taken up in coaling and repairing scraper tackle.

"In June, thirteen days' work increased the depth of water throughout the channel formed by the Essayons to seventeen feet eight inches, as shown by survey made on the 18th, at which date work was virtually suspended."

On the 28th, while helping a very heavy vessel over the bar, another blade of the forward screw was broken, and, on inspection, the vessel was found unfit for further work until thoroughly overhauled and repaired.

I sum up the time actually employed in work on the bar at Pass à Loutre and the results as follows:

From the 3d of September, 1868, to the 3d of February, 1869, out of 153 days, only 113 days' work with the dredging screw, and 16 days' additional with the rake. The condition of the bar not improved.

From the 3d of February to the 18th of June, 1869, 135 days, with 573 days' work on the bar, resulting in a clear, direct channel across the bar 175 feet wide at its narrowest part, and giving seventeen feet eight inches as least depth of water. The increase in depth at the crest of the bar was six feet two inches.

From this showing it may be fairly inferred that continuous work would have cleared a channel giving twenty feet, (the full depth to which the Essayons can work.)

During the first half of the fiscal year, the steam machinery of the Essayons gave great trouble, but after the 1st of January, 1869, worked in the most satisfactory manner, leaving but few alterations to desire. The greatest difficulty and delay arose from the frequent and unavoidable breaking of the blades in the dredging screw.

These blades being made of cast iron, having a lever arm of six feet revolving, when at work, with a circumference velocity of twenty feet per second, and being subject to frequent severe shocks from striking mud lumps, timber imbedded in the sand, and ballast deposited on the bar by vessels lightening over, were necessarily the most liable to accidents of any portion of the vessel, and, at the same time, the most troublesome to replace.

During the year ten of these blades were broken, as above indicated, and during nearly the whole of the working time reported, but two blades in the dredging screw were serviceable.

The substitution of the new blades for those broken several times necessitated docking the vessel, at an average expense of $700 per blade, not including cost of new blade.

To avoid, if possible, future expense and delay in the work, (which cannot be avoided with the screw as at present constructed,) it is recommended to substitute for the screw now in use one of greater strength, the additional strength to be gained by casting the blades of Bessemer steel, and by modifying the form of the blades and hull so as to give a greater cross-section to the pintle of the blade at the point subject to the greatest strain.

The shaft boxes, through the dead wood, are arranged to admit water from the outside for the purpose of cooling the shaft. This water, while the vessel is working, is full of mud and sand stirred up from the bottom of the river by the screw, and causes the rapid wear of both shaft and packing. So great has been the damage from this cause that I do not

consider it safe to work the forward screw, until the packing (and it is presumed the brass bearings of the shaft) are renewed. I propose, as a remedy for this defect, to close the end of the shaft box and carry surface water through iron pipes from amidships, to give the necessary supply; the water after use to be discharged inside the vessel and pumped out with the bilge-water.

The rake designed to aid the screw in stirring up the material of the bar is not of sufficient weight or length to be most effective, and should be so constructed as to scrape or carry as well as loosen. The vessel has a surplus of power that can be used to advantage in this manner.

As now arranged, the rake engine and the pumps are worked direct from the main boilers and to a disadvantage, owing to the low pressure under which the latter are run; not only one half the power of the rake engine can be developed with low pressure feed, and in consequence the handling of the rake has not been as rapid as could be desired. It is often necessary to run the pumps after working hours, and to keep up steam in one of the boilers to do so, at considerable expense for fuel, and with additional wear of boilers, which is an item of importance in view of the great cost and short lives of marine boilers in Mississippi River water. The useful effect of one boiler is taken from the main engines during the whole time of work. From consideration of the above, I would recommend a high pressure donkey boiler, placed in one of the after coal bunkers, and drawing through the main chimney, for the use of the pumps and rake engine.

I would also recommend, should the rake engine now in use not give sufficient power with high pressure feed, the substitution for it of an engine of fifteen horse-power.

The present cabin is not large enough for the proper accommodation of the officers of the vessel. I propose three additional state-rooms to be built over those now in use, and in extension of the two pilot-houses.

The foregoing are the only important modifications and additions I have to recommend at present; others will no doubt be suggested when the vessel is thoroughly overhauled, as is proposed to be done this summer. General repairs to hull and machinery are necessary, and have been specified in previous report.

The distance of Pass à Loutre from a coal market, together with the difficulty and expense which would attend the construction of a coal depot within a desirable distance of the work to be done by the Essayons, led to the purchase by General McAlister, in April, 1868, of the two-masted barge Cavallo, measuring 212.54 tons, as a tender. This barge has, since her purchase, been constantly employed in supplying the Essayons with coal from New Orleans, and for the storage of supplies of all kinds required on the work at Pass à Loutre. Her services have been of great value, both on the score of economy in the items of transportation and storage, and in the facilities she has afforded for carrying on the work regularly. She was purchased for $5,000.

I would recommend that as soon as it can be done without extra expense she be hauled up on the ways and her bottom examined and repaired. It will probably be necessary to sheathe her either with wood or zinc, as she has not been out of the water for nearly a year and must be worm eaten; how badly cannot be determined until she is taken

out.

The frequent accidents to the dredging screw of the Essayons, which necessitated entering a dry dock for repairs several times during the fiscal year, were taken advantage of by the Dry-dock Association of New Orleans to extort an exorbitant rete for dockage from the government.

The Essayons was classed as an extraordinary vessel, and charged double rates, or $812 for entrance, instead of being taken at regular rates and charged for tonnage over her measurements, as is the custom when merchant vessels loaded are taken up.

To protect the government from this imposition, Brevet Colonel F. E. Prime (then in charge of this work) contracted for an end dock, which was built at an expense of $2,000, and was ready for use April 9, 1869, since which date her services have nearly repaid her cost. It will be necessary to partially recaulk her above the water-line, at slight expense. She is now in good condition with but a few seams open.

I cannot too earnestly recommend the completion of Gen. McAlester's plans for this work, by the early construction of a vessel similar to the Essayons, but of deeper draught, to take the place of the latter when disabled, and make the work continuous.

This recommendation of General McAlester has gained weight from the experience of the past year, and there can now be no doubt of the successful opening of the Mississippi River to vessels drawing twentyfour feet, if his plans are fully carried out.

Another rcommendation made by General McAlester I would again call to your attention as of the first importance, having in view the proper preservation of the channel after it is formed. I refer to the appointment of some person officially charged with regulating the time, order, and manner in which vessels shall make use of the channel across the bar, and with lighting the buoys at night.

I would suggest as important regulations that "but one vessel at a time be permitted over the bar," and that sailing vessels be required to take a tow both in and out. The object in view is the preservation of grounding on the sides of the channel, and either blockading or shifting it from its present direct course.

I may here explain, in further support of the recommendation, that certain unscrupulous parties interested in maintaining the intricate and difficult entrance via South West Pass, without the check proposed, will at any time have it in their power to temporarily blockade Pass à Loutre, to the great inconvenience of commerce and hindrance of the work.

The commerce of New Orleans has been for so long a time dependent on the navigation of South West Pass, and on the pilots and tow-boat association controlling it, that ship-owners and shipping agents are slow to grasp the advantages offered by the work at Pass à Loutre.

On taking charge of this work in June, 1869, I found that not one vessel of considerable draught had essayed the channel formed by the Essayons, although during the entire month of May seventeen feet clear, and a direct channel 175 feet wide, had been publicly reported by the officer in charge as available at Pass à Loutre.

The actions of owners and agents was accounted for in two ways:

1. The tow-boat association, if they could avoid it, would not send their boats or tows via Pass à Loutre, and masters would not return through that pass without having assistance at hand, for fear of grounding.

2. The South West Pass pilots and tow-boat association persistently misrepresented the condition of Pass à Loutre, and their reports gained credence with many, in preference to the reports of the officer in charge of this work.

For the purpose of refuting in an unanswerable manner these false reports, and showing the value and amount of work done by the Essayons, her master (Captain Putnam) received orders to tow out or in all