various metals, including tungsten, tantalum, and molybdenum, which are of the highest importance in the incandescent-lamp industry. The results furnish a complete and convincing proof that the high luminous efficiency of such lamps is due to their selective emission in the visible spectrum, and a high reflecting power in the infrared. A new radiometer and a new quartz spectrometer have been constructed and found to be more sensitive than any yet described in print.

An important research resulted in the development of a new apparatus for measuring light waves to be used as standards. This subject is of fundamental importance, since it underlies optical standardization and research. With the new apparatus the relative length of light waves may be determined with high accuracy and great facility.

POLARIMETRY.

In its polariscopic work this Bureau must produce sugar of high purity under controlled conditions. During the year standard samples of pure sucrose prepared at the Bureau with certificates of analysis were widely distributed for calorimetric and polariscopic purposes.

Satisfactory progress has been made in the determination of the correct basis of standardization of saccharimeters-a vital problem to the sugar industry, as it affects directly the government revenues from sugars as well as the market price of every pound bought and sold. The business of the sugar industry is transacted by means of the saccharimeter, yet no official investigation of the basis of standardization of this instrument has hitherto been made. During the year special apparatus has been developed to attain this end and very pure sugar was prepared from raw sugars of widely different origins and compared with the pure sugar of other investigators in this country and abroad.

The present methods of testing molasses are being improved, a number of unusually dark samples being sent to the Bureau for test. As the tariff is six times the usual duty for imported molasses testing 40 per cent and above, the problem is vital to the customs service. The problem of increasing the accuracy of the sugar tests made at the ports of entry on imported sugar has received much attention and changes in apparatus and methods have been made, with gratifying results. The work of the Bureau has lowered the differences between the five sugar ports to less than 0.2 per cent, a concordance which is quite satisfactory. In all 1,339 polarimetric tests were completed during the year, besides the investigations in progress.

ENGINEERING.

The work of testing of engineering instruments and structural and other materials has steadily advanced. Additional space for the work has been provided and the erection of machines and instruments is now under way in the new laboratory. A 100,000-pound universal testing machine, already erected, has shown accurate and reliable results. The Bureau has also installed a 1,000,000-pound Riehle crushing machine for testing stone, brick, terra cotta, cement, and concrete, and for determining the moduli of elasticity of building materials and structural forms. A 2,400,000-pound Emery machine will soon be installed for investigating physical properties of materials and the constants required by engineers in computing structural designs. The construction of the large Emery machine for testing full-sized structural members and shapes is well advanced and the foundation is in place. Freezing chambers and special furnaces for fire tests of ceramic materials are being built. Investigations are also in progress as to methods of testing torsion, cold-bending, alternating impact, alternating stress, and hardness.

A new method of determining stresses and strains in large structural members used in bridges and buildings has been devised and tested on the Rock Creek Bridge, at Washington, D. C., and on the Ohio River Bridge, at Beaver Falls, Pa. This new method promises fruitful results in testing the safety of bridges and buildings while under construction and without the use of large testing machines. The method is also applicable to a study of lap-welded boilers and the deformation resulting from stresses.

The bureau tests have covered a wide range of metals and structural materials and have been made for all the government departments, and for the Public Printer, Panama Canal Commission, Superintendent of the Capitol, and the Commissioners of the District of Columbia. The number of tests of miscellaneous materials, such as paper, textiles, cordage, belting material, hose, packing, and lubricants, has increased 50 per cent. With special equipment the Bureau is to make investigations and assist in preparing standard specifications for government materials and to aid in the adoption of uniform standards in the industries.

The Bureau tested four times as many engineering instruments as in the previous year, including anemometers, pressure gages, paper testers, and water-current meters. The Geological Survey has transferred to the Bureau the Chevy Chase Lake station for calibration of water-current meters. The station has been improved and an investigation of Price meters is now in progress.

CHEMISTRY.

There has been a large amount of chemical testing of materials supplied under contracts of the General Supply Committee. Related to this is the work of testing important reagents. The systematic reporting of discrepancies to the manufacturers will result in greater care in the manufacture and increased accuracy in the analysis of reagents.

The Bureau cooperates in movements looking to higher standards of excellence of materials whose value largely depends upon their chemical nature and purity. The Bureau is represented on important committees of the American Chemical Society, such as the committee on specifications for rubber goods, the committee on the nomenclature of inorganic compounds, the committee on the analysis of fat and oils, and the committee having general oversight of the various special committees of that society.

The demand for the analyzed and certified standard samples of iron and steel is still increasing, the number distributed having been 717. These are used as a check upon the accuracy of industrial analyses. Two new Bessemer steel standards have been issued, several are in preparation, and renewals of two of the basic open-hearth samples are being prepared. The demand for the original standard irons is such that renewals of three of them have been prepared in large quantity. A manganese ore and three iron ores have been added to the list of standard samples. A red cast brass standard has been prepared and a method of preparing sheet-brass samples has been worked out.

During the year there were completed about 1,757 tests and analyses, such as printing inks, paper, mucilage, pastes, and sealing wax; metals, especially type metal and similar alloys; reagents; paints, oils, and greases; rubber hose, valves, etc., and miscellaneous, such as submarine cable, book cloths, bricks, etc. These were largely contractual tests, but in cases where existing methods of test are inadequate, new methods are being devised. Progress has been made in standardizing such materials and the methods of test, although much remains to be done.

58169°- -C & L 1910- -6

BUREAU OF FISHERIES.

The fortieth fiscal year of the Bureau's existence, which came to a close on June 30, 1910, has been its most successful one as measured by the volume and variety of its activities. The natural development of its older functions and the execution of the newer ones with which it has been recently invested have each operated to bring it into more important relations to the fisheries in both their local and national aspects.

PROPAGATION OF FOOD FISHES.

In fish culture there have been no radical departures from former methods, but as a result of experience and effort it has been possible to secure greater accomplishment with essentially the same appropriations and equipment that were available in the preceding year. Operations have been conducted at 35 hatcheries and 86 field stations located in 32 States, and no part of the country has been omitted from participation in the benefits of the work.

That the public generally, and especially that part of it interested in the commercial and sporting fisheries, is keenly alive to the benefits of stocking virgin waters and restocking depleted ones with the fishes hatched by the Bureau is shown by the 10,635 applications for fish received during the year, an increase of 523 over those received in the preceding twelve months. In addition to the fish planted in response to these requests, by far the larger part of the output, especially of the more important commercial species, was planted by the Bureau on its own initiative in the waters subject to the heaviest fisheries.

Despite the generally unfavorable climatic conditions, resulting in the curtailment of egg collections, the total output of fish and eggs was over 3,230,000,000, the greatest in the history of the service, and nearly 125,000,000, or 4 per cent, in excess of the output of the preceding year. Notwithstanding the magnitude of the work, it can be extended to advantage, and there appears to be a promising field by increasing the facilities for stocking small ponds and streams so as to furnish a local or home fish supply in rural communities which are now deficient in that respect. There is probably no undertaking better adapted to bring the Bureau into closer and more profitable relations with the public at large.

SCIENTIFIC RESEARCHES AND EXPERIMENTS.

To supply data necessary for purposes of legislation in connection with the fisheries, the governor of Virginia at the instance of the state fish and oyster commission early in 1909 preferred a request for a

survey of the public oyster beds of James River. The field work was carried on from July 1 to September 15, the season when the beds are in their optimum condition, and a comprehensive report with elaborate charts showing in detail the extent and character of the beds was issued and placed in the hands of the legislature at its session in January. It is regretted that the highly desirable legislation which the state commission recommended upon the basis of this work and proposed to the legislature failed because it was supposed to be in conflict with certain constitutional provisions.

A similar survey of the public oyster beds of Delaware, in the prosecution of which the State bore a share of the expenses, was undertaken in June, 1910, and was in process at the end of the fiscal year. The survey of the oyster grounds in Maryland, in which the Bureau is cooperating with the Coast and Geodetic Survey and the Maryland Shell-Fish Commission, was continued and the field work was nearly completed at the close of the fiscal year.

The experiments in fattening oysters under artificial conditions at Lynnhaven, Va., produced encouraging results, and in the latter part of the season there were practically no fat oysters produced in that region excepting those coming from the Bureau's experimental plant. At the request of the state authorities the oyster beds of Alabama and Mississippi received a preliminary examination, and a survey in the interests of oyster culture will be made during the coming year.

Investigations of the pearl-mussel beds of the Mississippi Valley, the material depletion of which threatens the prosperity of the important pearl-button industry, have been prosecuted in ten States with a view to opening new sources of supply for the manufacturers and for the purpose of laying a foundation for the protection, conservation, and improvement of the existing beds. The recently authorized station at Fairport, Iowa, should be of great value in helping to maintain and develop the button industry; and it is gratifying to be able to report that at the end of the fiscal year construction was so far advanced as to permit the beginning of practical experiments on a small scale.

Diseases of fishes under the artificial conditions necessarily attendant upon operations at hatcheries appear to be growing, or at least the Bureau is more frequently called on by state officials and private persons and by its own service for advice and assistance in their diagnosis and treatment. The work is much hampered by the lack in the United States of either public or private facilities for the study of the problems involved, and but little progress is being made. In some cases the epidemics are disastrous and in a short time negative the results of years of work. Not only are the United States, the States, and individuals annually sustaining heavy financial losses through ignorance of the nature of the troubles, but there is a