SURVEYS AND EXAMINATIONS WITH THE VIEW TO THE IMPROVEMENT OF RIVERS AND HARBORS.

For continuing these examinations and surveys, and to provide for contingencies of works of river and harbor improvement during the fiscal year ending June 30, 1873, an appropriation should be made of $200,000.

RECONNAISSANCES AND EXPLORATIONS.

The officers of the Corps of Engineers on detached duty at the headquarters of the general officers commanding divisions and departments have been engaged during the past year in preparing such maps and sketches and making such surveys and reconnaissances as were required by their respective commanding officers.

RECONNAISSANCE OF THE YUKON RIVER, ALASKA TERRITORY. The final report of Captain C. W. Raymond, Corps of Engineers, who was temporarily assigned to duty in the Military Division of the Pacific for the purpose of making this exploration, was transmitted to Congress April 15, 1871, and printed in Ex. Doc. No. 12, Forty-second Congress, first session. Captain Raymond accomplished, in a highly creditable manner, the duties intrusted to him in this hazardous expedition.

EXPLORATION OF THE TERRITORY SOUTH OF THE CENTRAL PACIFIC RAILROAD, EMBRACING PARTS OF EASTERN NEVADA AND ARIΖΟΝΑ.

Officer in charge, First Lieutenant George M. Wheeler, Corps of Engineers, who had under his orders First Lieutenant D. W. Lockwood, Corps of Engineers.

The main object of this exploration is to obtain correct topographical knowledge of the country traversed, and prepare accurate maps of it. Also, to ascertain the physical features of the country; numbers, habits, and disposition of the Indians; the selection of sites for future military occupation or operations, and the facilities offered for making \ common or rail roads; the influence of climate; the geological formation, character and kind of vegetation; latitude and longitude of important points, &c., &c.

Lieutenant Wheeler gave his personal attention to the arrangement of preliminaries, and with his parties took the field about May 1. Since that time the exploring parties have been occupied south of the Central Pacific Railroad, and along sections bordering the reconnaissance made by Lieutenant Wheeler in 1869, and over sections in southwestern Nevada, southeastern California, south western Utah, northern, northeastern, and eastern Arizona, the field-labors of which will close early in December.

The area examined in 1869 by Lieutenant Wheeler, after being increased by the sections explored during the past year, will still leave large districts of country unexamined south of the Central Pacific Railroad, and to continue these explorations will require further appropriations, an estimate for which, of $100,000, is submitted by the officer in charge.

FROM THE SIERRA NEVADA TO THE ROCKY MOUNTAINS.

The geological and topographical exploration of the territory between the Sierra Nevada and Rocky Mountains has been continued. Mr. Clarence King, United States civil engineer, in charge

Since my last report, Vol. III, Mining Industry, has been published and partially distributed. The volume on botany is in press. That of zoology is in the hands of the printer.

A report of Mr. King, dated February 14, 1871, appended herewith, (Appendix Z,) gives a general outline of the operations of the parties engaged in this work, and a brief notice of the results attained.

During the working season of 1871, the observations and operations of the party have been confined to the region contiguous to the Pacific Railway, and to the eastward of the one hundred and eleventh meridian, embracing portions of Utah, Wyoming, and Colorado. It is expected that the field-work will be closed about December 1.

Under date of October 3, Mr. King, in reporting the monthly progress, states that one of his parties entered Uintah Range, near the head of Black's Fork of Green River, on August 26, and from that date extensive fires have raged throughout the entire Rocky Mountains, filling the air with such volumes of smoke as to altogether stop topographical work. A second party, on the 27th of August, moved from Fort Sanders into the North Park and Elk Head Mountains, and there encountered the same obstacle to the prosecution of their work. While the smoke interfered with the topographical work, they were, however, able to continue their geological investigation, and Mr. King reports that the results are very satisfactory. This letter is appended hereto, (Appendix Z 1.)

MISCELLANEOUS.

MAPS OF CAMPAIGNS AND BATTLE-FIELDS.

Maps of the campaigns of the western armies are being prepared by Colonel E. L. Ruger, late of the United States volunteers. The map showing the second epoch of the Atlanta campaign, embracing the region from Resaca to the Etowah River, is finished; also, that showing the third epoch south of the Etowah and embracing the battle-fields of New Hope, Church, and Dallas.

SUBDIVISION AND SALE OF A PORTION OF THE FORT GRATIOT MILI TARY RESERVATION.

The acts of Congress approved July 20, 1868, and March 18, 1870, provided for this subdivision and sale. Under this authority and instructions from the War Department a survey was made and a map prepared embracing the subdivision of a portion of the reservation into lots of convenient size, which was transmitted to, and approved by, the honorable Secretary of War.

After due advertisement according to law the sale at public auction commenced on the 14th and closed on the 16th of December, 1870; the aggregate amount realized therefrom being $41,524 for a total of 242 lots, deeds for which have been executed and delivered to purchasers. A further subdivision was made and sale advertised to take place, beginning on the 8th of August, 1871.

The appropriation specially applicable to the purpose of defraying expenses incurred in the subdivision and sales referred to is

Of which there has been expended to June 30, 1871, in

clusive...

Balance...

$3,000 00

2, 440 42

559 58

This balance is so small that it will be difficult to keep the indispensably necessary expenses within the limit.

ESTIMATES OF AMOUNTS REQUIRED FOR MILITARY AND GEOGRAPHICAL SURVEYS AND RECONNAISSANCES.

To carry on these surveys and reconnaissances during the next fiscal year there will be required an appropriation of $150,000.

SUTRO-TUNNEL COMMISSION.

By act of Congress approved April 4, 1871, the President of the United States was "authorized and requested to appoint a board of three commissioners, two of whom shall be officers of engineers of the Army and one a mining or civil engineer, to examine and report on the Sutro Tunnel in the State of Nevada, authorized to be constructed by an act of Congress, approved July 25, 1866, with special reference to the importance, feasibility, cost, and time required to construct the same; the value of the bullion extracted from the mines on the Comstock lode; their present and probable future production; also, the geological and practical value of said tunnel as an exploring work, and its general bearing upon our mining and other national interests in ascertaining the practicability of deep mining."

By direction of the President, Lieutenant Colonels H. G. Wright and John G. Foster, Corps of Engineers, were appointed members of the commission on the 27th April, 1871, and Professor Wesley Newcomb, of Ithaca, New York, a inining and civil engineer, on the Captain W. R. King, Corps of Engineers, in addition to his other duties, was directed to act as secretary of the commission.

On the 1st of June instructions were issued by the Chief of Engineers to Lieutenant Colonel Wright, senior member, directing him to convene the commission in New York City, or other convenient place, to proceed to the business devolving upon it, and, as soon as practicable after organization, to proceed to Nevada and make the investigations called for in the act, at or near the site of the tunnel, and having completed the investigations called for, to return to New York City and prepare the report, and, if practicable, submit it previous to the 1st of Decem

ber.

On the 20th of June the commission proceeded to the scene of its duties, where it remained until August 8, when it adjourned to meet in New York City September 15, where it is now engaged in preparing the report.

OFFICE OF THE CHIEF OF ENGINEERS.

I beg leave to invite your attention to the serious inconvenience the business of this office suffers from the restricted space available for its use, and of the unsuitableness of the rooms for the preservation of the valuable maps, drawings, and other records which are of necessity placed in them.

In the labors of the office I was assisted on the 30th of June by the following officers in charge of the several divisions:

FIRST AND SECOND DIVISIONS.-Fortifications, battalion and depots, lands, armaments, personal, &c., Major T. L. Casey.

THIRD DIVISION.-River and harbor improvements, &c., Major J. G. Parke.

FOURTH AND FIFTH DIVISIONS.-Property accounts, estimates, funds, survey of lakes, explorations, maps, instruments, &c., Major J. B. Wheeler.

Very respectfully, your obedient servant,

A. A. HUMPHREYS,

Brig. General, Chief of Engineers, commanding Corps of Engineers. Hon. W. W. BELKNAP,

Secretary of War.

OFFICE OF THE CHIEF OF ENGINEERS,

Washington, D. C., November 2, 1871.

SIR: I beg leave to transmit herewith a report received this day from Major N. Michler, Corps of Engineers, late in charge of public buildings and grounds in this District, of the public works under his direction during the fiscal year ending June 30, 1871.

This report should have been transmitted to this office in time to be submitted in my annual report of the 20th ultimo, but it may still be attached thereto as an appendix.

Very respectfully, your obedient servant,

A. A. HUMPHREYS, Brigadier General and Chief of Engineers.

Hon. W. W. BELKNAP, Secretary of War. (Appendix X 3.)

APPENDIX.

APPENDIX A 1.

Annual report of Major D. C. Houston, Corps of Engineers, for the year ending June 30, 1871.

IMPROVEMENT OF DU LUTH HARBOR, MINNESOTA.

An appropriation of $60,000 having been made for the improvement of Du Luth Harbor, I was directed to apply this sum to the extension of the breakwater already built by the railroad company in the lake at that place. In pursuance of instructions I advertised for proposals for this work, and on the 24th of June, 1871, made a contract with Munger & Gray to extend the breakwater 500 feet. It is proposed to put in ten eribs, 50 by 30 feet, this season, leaving the superstructure above water till next spring. The amount appropriated will build the extension and repair the breakwater built by the railroad. This work is unusually exposed, and is liable to serious injury from the effects of large masses of ice, which are hurled against it during storms. The most secure protection of the work is now in process of formation by the action of the lake; the drift of shingle along the lake is arrested by the breakwater, and is now forming a beach of clean gravel extending over 100 feet from the shore line above water. This is constantly forming, and will, in time, form an effectual protection of the work. Minnesota Point, which separates Lake Superior from the Bay of Superior, is composed of the same material for a distance of nearly two miles from the north shore of the lake, and is believed to have been formed in the same way. It is proposed, however, to protect this work by a sheathing of oak timber placed vertically and bolted to the superstructure. These timbers to be 10 inches square, and placed 3 feet apart from center to center, to be about 8 feet in length. It is also proposed to raise the superstructure to 6 feet above water, and deck it over with plank or timber.

It is proposed to make this breakwater 3,000 feet in length, including the present work, which is 400 feet in length. The present appropriation will extend it 500 feet at least, leaving 2,100 feet to be built. The city of Du Luth is now engaged in cutting a canal through Minnesota Point, to connect the lake with the bay. Very little dredging, and of an easy nature, is necessary to make a splendid harbor at the upper end of the bay. This work is now being carried on with the consent of the Government, upon the condition that the city construct a dike, which shall prevent the waters of the St. Louis River from being diverted through the canal to the possible injury of the harbor of Superior City, Wisconsin, now being improved at large cost by the Government. With the completion of the canal, and the excavation of the bay, Du Luth will be abundantly supplied with harbor accommodations, and the extension of the breakwater further than is necessary to protect the docks now existing seems unnecessary. The extension now in progress will be sufficient to protect present improvements on the lake shore. Should future appropriations be made for this harbor, there will be a question as to their proper application, if the canal project is carried into effect.