General.--The geologist in charge has been chiefly occupied in routine administrative work. In July, 1905, he visited the parties working in southeastern Alaska and in the Controller Bay region. Considerable time was also spent on a report entitled "The gold placers of Seward Peninsula," which is now nearly completed.

SEASON OF 1906.

Under a continuation of the same appropriation 12 parties were dispatched to Alaska during the months of May and June, 1906. Of these, one topographic and one geologic party were sent to southeastern Alaska. A geologic party went to the St. Elias region and one to complete the mapping of the Controller Bay region. The region lying adjacent to the upper end of Cook Inlet is to be surveyed by two parties. A geologic party is to continue detailed work in the Nome region. By cooperation with the division of hydrography stream gaging was begun in the Nome region. Two topographic parties are continuing reconnaissance surveys in the Yukon-Tanana region. One geologic party has been dispatched to the newly discovered Kantishna placer district and another has been directed to work along the upper Yukon.

DIVISION OF MINING AND MINERAL RESOURCES.

During the year ending June 30, 1906, the division was engaged in the preparation of the reports on the mineral resources of the United States for 1904 and 1905. The report for 1904 was completed and published, and the report for 1905 is approaching completion. Manuscripts for most of the chapters are in hand, and some of them have already been published as advance extracts. The reports received indicate that the total value of the mineral products of the country in 1905 may exceed the value in 1904 by 10 per cent.

The work on the black sands of the Pacific coast, which was authorized by Congress and organized before the fiscal year began, was pushed vigorously during the year at Portland, Oreg., where exceptional facilities for this work were offered by the Lewis and Clark Exposition. The results have exceeded all expectation, and the investigation bids fair to lead to the development of an important and lucrative industry in the utilization of the black sands of the country as a source of gold, platinum, iron ore, and some of the rare metals. It is highly important that this work be continued on the Pacific coast and that it be extended to the promising fields along the Atlantic seaboard.

A considerable portion of the time of this division is consumed in answering technical inquiries, and laboratory facilities should be afforded the division for making simple tests for determining the mineralogic character of the large number of specimens submitted to

it annually. It is not intended that the work of this division should take the place of the commercial chemist, but merely that it be placed in a position to advise correspondents of the nature of specimens submitted and whether or not the material is worth further investigation. The chief of the division has been designated by the Secretary of the Interior to cooperate with the Jamestown Exposition Company in the organization of a mining exhibit at the exposition, to be held in 1907.

DIVISION OF CHEMICAL AND PHYSICAL RESEARCH.

During the year 144 analyses were reported from the laboratory, together with 567 determinations of minerals received from various sources. This, with the usual amount of administrative detail, correspondence, etc., represents the routine work of the laboratory.

Apart from the routine, the scientific work of the division has been as follows:

Progress was made on a monograph of geochemistry, and the first draft of the manuscript is approaching completion. Much work was done on analytical methods, especially with reference to the determination of the moisture in coals, of fluorine, ferric iron, and manganese in rocks, and a revision of Bulletin No. 176 is nearly completed. A considerable number of rare minerals was examined, especially a series of unusual ores of mercury from Texas. Progress was made upon a research into the secondary enrichment of ores. An investigation was made upon the determination of manganese and zirconia in rocks. A large amount of work was done upon crystallographic measurements, especially of the mercury minerals referred to above. Studies were also made upon the minerals of the lithia region of California.

In the physical laboratory, after completion of the memoir on "The isomorphism and thermal properties of the feldspars," two other series of minerals were taken up, in order, if possible, to carry thru an equally careful investigation of some typical eutectic series. The minerals chosen for these studies were the magnesium silicates and the lime silicates. A paper on " Wollastonite and pseudowollastonite, polymorphic forms of calcium metasilicate," was completed and pubblished, and a paper on a very interesting and complicated tetramorphic relation occurring in the magnesium silicate series is now nearly ready for publication. As a part of the same general plan of investigation, another investigator was engaged upon the limestone series, studying all possible stable forms from pure lime to pure silica. A careful investigation was also made of the phenomena attending the melting pure silica (quartz); this has immense technical interest on account of the value of quartz glass, which can be heated white hot without softening and while still hot be plunged into water without breaking.

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The more interesting facts developed in the experiments upon quartz were published in Science during the year. A paper on the calcium silicates is nearly ready for the printer, and considerable progress can be reported upon a fundamental investigation of the scale of temperatures in terms of which all the work of the laboratory is exprest. The existing German scale extends only to 1,150° C., which is insufficient for effective work with the minerals. A gas thermometer was therefore constructed, and after several months of preliminary work it is possible to say that greater accuracy as well as greater range bas been attained.

Members of the division have been engaged, also, in the study of finite elastic strains, as an incident to which a useful series of mathematical tables was prepared.

TOPOGRAPHIC BRANCH.

The organization of the topographic branch remained the same as it had been during the two immediately preceding years.

COOPERATION BY STATES.

Cooperative arrangements for topographic surveys were made with fourteen States. The governor of the State of Illinois allotted $10,000; the legislature of California appropriated $15,000; the director of the Kentucky Geological Survey allotted $5,000; the State Survey Commission of Maine, $3,200; the State geologist of Maryland, $2,500; the State geologist of Michigan, $2,000; the State engineer and surveyor of New York, $600; the commissioner of agriculture of North Carolina, $4,000; the governor of the Territory of Oklahoma, $5,000; the governor of Ohio, $23,800; the governor of Oregon, $2,500; the State Survey Commission of Pennsylvania, $14,000; the State geologist of West Virginia, $15,000; and $400 was allotted by the forestry commission of New Hampshire for a special sheet. Thus $103,000 was allotted by the States mentioned, in addition to the Federal appropriation for topographic work

SUMMARY OF RESULTS.

The following summary includes all small-scale topographic surveys made by the divisions of topography, including those of forest reserves, and by the division of Alaskan mineral resources:

Primary azimuth observations were made at two triangulation stations. Triangulation stations to the number of 328 were occupied or located and marked, and 3,261 miles of primary traverse were run. In the course of this work 51,430 square miles were covered by primary control.

The condition of topographic surveys to June 30, 1906, distinguished as to scale, etc., is shown on a general map of the United States, Pl. I,

On

and the detailed distribution of this work in the various States and Territories is shown on the accompanying maps, Pls. II-XXIII. the latter are indicated by proper symbols the sheets published to June 30, 1906, the sheets in course of publication, and the areas surveyed during the field season of 1905 and drawn in map form in the office season of 1905-6. By appropriate symbols these maps also show areas in which precise or primary spirit levels have been run and unmapped areas which are controlled by primary triangulation or traverse or by astronomic positions.

As shown in the following table giving the details of topographic mapping and spirit leveling for the fiscal year, the total of new surveys was 36,605 square miles. The total area surveyed in the United States to date is 992,601 square miles, or about 32 per cent.

In addition, 3,179 square miles of revision or resurvey were completed by final topographic mapping in the eastern division and 1,01€ in the western division, over which preliminary reconnaissance surveying had been previously carried, thus making the total area of actual surveys for the season 40,800 square miles.

In connection with these surveys there were run 38,307 linear miles of spirit levels, of which 892 miles were precise, making the spirit leveling done since the authorization of this class of work by Congress, in 1896, amount to 196,371 miles. In addition, 327 miles of forestreserve boundary lines were run, 12 miles were retraced, and 15 miles of supplemental lines were run.

The total area covered by topographic surveys made in Alaska during the fiscal year 1905-6, as reported in detail on pages 25-26, was about 5,300 square miles, in the course of the mapping of which 191 miles of spirit levels were run and 26 permanent bench marks were established.

Present condition of topographic surveys of the United States, and new areas surveyed in