mund experiment station. Charles E. Munroe, consulting explosives chemist, and George S. Rice, chief mining engineer of the Bureau of Mines, represented the United States, and the latter acted as secretary of the conference. William O'Connor, a mining engineer of Wales, was invited to take part in the meeting as an unofficial representative of Great Britain. J. Taffanel, director of the Lievin experiment station, who was to have represented France, was unexpectedly recalled just before the conference on account of a mine disaster.

Most of the time allotted to the conference was spent in reading papers and discussing investigations at the Pittsburgh experiment station and in observing coal-dust explosions at the experimental mine.

The delegates agreed that it was desirable to form a permanent organization; that the approval of the various nations to the forming of the organization and the appointment of the delegates be effected through the regular diplomatic channels; and that the next meeting of the conference be held, if possible, in 1914 in England or Belgium.

WORK OF MINE-RESCUE CARS AND STATIONS.

During the year over 46,000 persons (mainly miners) visited the mine-rescue cars and stations maintained by the bureau, nearly 33,000 miners attended the mine-safety lectures, and more than 6,000 miners were given rescue or first-aid training. Miners and operators in all coal fields have taken active interest in the demonstration work of the bureau, and the number of operators who have organized and equipped mine-rescue corps at their own mines at their own expense has shown a most gratifying increase.

During the year car 8, with headquarters at Ironwood, Mich., began service in the copper and iron mining districts about Lake Superior. The work done by the crew of this car was received with much enthusiasm and both mine operators and miners have testified to its value. Some instruction was given in a few metal-mining camps in Colorado, notably at Aspen and Cripple Creek. At Aspen the crew of car 2 rendered valuable service in controlling a serious mine fire that threatened to stop mining operations.

MINERAL-TECHNOLOGY INVESTIGATIONS.

Perhaps the most striking result of the year's work was the demonstration of the value of the uranium and vanadium ores of Utah and Colorado as sources of radium, the losses attending the present methods of mining and marketing, and the need of developing methods by which the radium may be recovered in this country. Already,

as a result of the bureau's investigations, producers of these ores have obtained better prices, waste has been lessened, and at least one American firm is making radium salts.

As a result of other investigations, the bureau has pointed out the preventable losses in the mining and treatment of feldspar in the Southern States and the saving to be obtained, to the resulting profit of many small operators, by the use of simple but efficient methods; has demonstrated the high quality of deposits of fuller's earth in this country and the possibility of using American fuller's earth to replace practically all of the fuller's earth now imported; and has ascertained present wastes in the production of nonferrous alloys and the advantages to be gained by the use of electric furnaces in the production of these alloys.

INVESTIGATIONS RELATING TO HEALTH CONDITIONS IN THE MINERAL INDUSTRIES.

Some progress was made in investigations relating to health conditions in mining and metallurgical industries, the occupational diseases common to certain callings, and the sanitary conditions in mining communities. The results of inquiries concerning health conditions in and about kaolin and feldspar mines in the Southern States and the sanitation of mining villages in the Birmingham district, Alabama, were published during the year, and the results of inquiries relating to occupational diseases in brass foundries and similar metallurgical establishments were prepared for publication.

FUEL INVESTIGATIONS.

Under the wording of appropriation acts, the fuel investigations conducted by the Bureau of Mines have been restricted to the analyzing and testing of fuels belonging to or for the use of the United States; consequently the various technologic researches and the routine work relating to the examination of fuels under this bureau related chiefly to two general lines of inquiry, as follows:

1. The inspection and analysis of coals, lignite, and other mineral fuels purchased under specifications for the use of the Government, to ascertain whether these fuels conform to the stipulations of the contract under which they are purchased, and the ascertaining of the most efficient equipment for burning these fuels.

2. The investigation of coal, lignite, and other mineral fuels belonging to the Government.

The work of inspecting and analyzing fuel purchases was improved and made more efficient during the year. The samples represented coal and fuel oil for use on naval vessels and at Government power

plants, public buildings, and naval stations in different parts of the United States and in the Panama Canal Zone.

In the fiscal year 1913 the purchase of coal by the Government under specifications providing for payment according to the quality of the delivered coal amounted to approximately 1,375,000 tons, costing $4,381,000, notwithstanding that the general plan was to apply the specification method of purchase only to contracts of such size as to warrant sampling and analysis, and heating-value tests, and that the specification method was not rigidly applied to anthracite purchases because of the many samples of anthracite already collected and analyzed and the small area of the anthracite fields.

Most of the samples analyzed at the Washington laboratory represented coal purchased under specifications that provided for payment according to the quality of the delivered coal. Analyses of samples collected in mines were generally made in the bureau's laboratory at Pittsburgh. During the fiscal year ended June 30, 1913, 7,607 samples were analyzed at the Washington laboratory, compared with 11,300 in the previous year.

The analyses and tests of fuels at the experiment station in Pittsburgh are made to indicate the character of the coal and other mineral fuels belonging to the United States, and to show how these fuels may be best utilized.

In analyzing samples of coal and lignite and other mineral fuels at the Pittsburgh station, the procedure followed was essentially the same as that of the Washington laboratory, except that at Pittsburgh ultimate as well as proximate analyses were made. Through the efforts of the chemists in charge of the laboratories improved apparatus and methods were devised and adopted with a view to lessening the cost and increasing the accuracy of the work of analyzing samples.

During the fiscal year 1913 about 635 mine samples of coal and lignite, 475 samples of fuel oil, and 293 samples of natural gas were analyzed in the laboratory at Pittsburgh. Of the oil purchased for the Navy, some 21,000,000 gallons in all was purchased under specifications prepared by the bureau.

The tests of fuels at the Pittsburgh station included studies of the process of combustion in boiler furnaces, undertaken in order to ascertain what proportions furnaces should have for the complete and smokeless combusition of fuels that are usually considered smoky, a study of the practical value of instruments used in boiler rooms for indicating the efficiency of combustion, and investigation of an electric device for precipitating smoke and fumes from chimney gases. An investigative study was made of waste from a coal mine on Gov

ernment property with a view to using this waste for generating power for the mine.

The fuel tests also included investigations of the various petroleums found throughout the United States with a view to determining their heating value, chemical composition, and the most economical methods for efficiently utilizing them as power producers, especially on board Government ships; and investigations of the heavier distillates of petroleum, as well as of kerosene and gasoline, in order to ascertain their relative efficiency in internal-combustion engines for use in naval vessels and for other purposes.

Related investigations concerned methods of mining and of preparing coal for market, and of boring for and transporting oil and natural gas, with a view to ascertaining how present wastes in mining, preparing, and transporting fuel may be most efficiently lessened.

During the year the bureau continued chemical and physical researches to determine the composition of the different varieties of coal, in order to ascertain how each coal could be burned most efficiently in a variety of Government power plants. Experiments were continued to ascertain the deterioration of coal during storage and the causes of spontaneous combustion of coal, with especial reference to fire risks in storing coal on board ships, in closed bins, or on wooden wharfs. The results obtained are mentioned in another part of this report.

PROGRESS OF THE INVESTIGATIONS.

COAL-MINING INVESTIGATIONS.

MINE DISASTERS.

The investigations of mine explosions and mine fires have brought out new information, and called attention to causes of explosions other than those mentioned in the report for 1912.

MINE EXPLOSIONS.

Further data have been obtained regarding the causes of mine explosions and the conditions that have tended to lessen or limit them, both through explosion tests at the bureau's experimental mine at Bruceton, Pa., and through the study of the effects of explosions in mines in different parts of the country. On the whole, there has been a decided decrease in the annual number of serious mine explosions, and in the fiscal year 1913 there was only one disastrous explosion, that at the Cincinnati mine, near Finlayville, Pa. The total number of lives lost by explosions of gas and dust annually per

1,000 persons employed has been decreasing since 1910, as shown by the following table:

Number of men killed by gas or dust explosions in coal mines in the United States, 1910-1912.

Mine operators have not fully recognized as yet the great dangers of using "mixed lamps”—that is, open lamps and safety lamps— in coal mines that make some gas and yet are not pronounced gaseous mines by State authorities. It is in such mines that the danger of an explosion is greatest. During the year there were no explosions in mines that employed safety lamps only.

In this country there are relatively few coal mines that give off a steady flow of methane. The gas is usually found when a clay slip or crevice in which gas has been confined under comparatively high pressure is cut, consequently a dangerous quantity of methane may accumulate in a heading soon after a test that failed to reveal the presence of gas.

The remedies for gas explosions are (1) to employ either oil-burning safety lamps or portable electric lamps that have passed the safety requirements of the bureau and have been approved as permissible; and (2) to render the coal dust inert, either by thoroughly wetting it by extensive watering or by humidifying the mine air, or, where water is scarce, by scattering plenty of clay or rock dust on all projections and timbers and on the floor. This mode of using rock dust has been recently adopted in France, and to a smaller extent in England, but has been used in only a few mines in this country.

In coal mines there is especial advantage in using portable electric lamps because they give more light that can be utilized than safety lamps, afford better illumination, decrease the danger of gas being ignited, and are more convenient to handle. Of course, in mines where these electric lamps are used the faces should be frequently inspected to ascertain whether dangerous quantities of gas are being given off.