After completing this general survey, the committee on reconstruction problems decided to limit its efforts to certain specific undertakings, which, as shown by the inquiry, have not been covered by other organizations. One of the most important and far-reaching of these is the research into details which relate to the control of water in its relation to food production and other industries.

At the present time there does not appear to be any one body or organization which is conducting a research into the mathematical, physical, and biological data bearing upon irrigation, drainage, flood control, and the application of these to engineering and agricultural science. It is recognized that many important undertakings are in the hands of several bureaus of the Government, each dealing with one phase or another of these subjects, and that a large amount of information has been collected and, by proper coordination, may be made available for research of the kind proposed.

The committee contemplates a report having to do with reconstruction, both at home and abroad, somewhat along the lines of a publication issued by the Division of Geology and Geography of the Council, entitled "Military Geology and Topography." The report, it is expected, will cover subjects of quantity, quality, and availability of water and its use in agriculture, power-production, and similar enterprises.

Under recent conditions the grouping, rounding out, and publication of data on water resources have peculiar value, since questions of water supply and control enter so largely into all reconstruction plans throughout the world.

In addition to the specific researches and preparation of the report referred to, the committee has also under consideration other lines of inquiry into reconstruction problems, which are in the course of development.

MILITARY DIVISION.

CHARLES D. WALCOTT, Chairman; S. W. STRATTON, Vice Chairman.

The Military Committee of the National Research Council, which was one of the first committees to be organized, was very effective in securing the necessary cooperation with the Army and Navy in the solution of research problems. Under the war organization this committee became the Military Division of the Council. The most valuable results of its work have been the organization of the Research Information Service and the authorization and organization of the weekly conferences on war problems of the Divisions of Physics and Engineering, in which representatives of the Army and Navy as well as the civil bureaus of the Government regularly participated (see report of Physics Division).

DIVISION OF PHYSICS, MATHEMATICS, ASTRONOMY, AND GEOPHYSICS. ROBERT A. MILLIKAN, Chairman; CHARLES E. MENDENHALL, Vice Chairman. The membership of the executive committee of this division, fully set forth in the war organization appended to this report, includes representatives of physics, astronomy, mathematics, and geophysics. Effective cooperation between the various services of the Government was also provided for through the fact that these members were connected, respectively, with the Signal Corps, the Bureau of Aircraft Production, the Bureau of Ordnance of the Navy, the Bureau of Ordnance of the Army, the Chemical Warfare Service, the Weather Bureau, the Advisory Committee for Aeronautics, the Bureau of Standards, and the Carnegie Institution of Washington. The meetings of the executive committee were devoted to the discussion of war problems, and also to the preparation of plans for the permanent organization of the Division of Physical Sciences, the formulation of policies regarding the Research Information Service, the organization of research in the Army, and the establishment of the weekly conference of the Physics and Engineering Divisions. This conference was of such importance in connection with the war that a detailed statement regarding it should be included here.

In the spring of 1918 the Military Committee of the National Research Council, upon the initiative of the Division of Physics, authorized the establishment of a weekly conference of the Physics and Engineering Divisions for the discussion of the new scientific and technical problems facing both the Army and the Navy. These conferences were held each Thursday evening throughout the remainder of the year at the office of the Research Council, and were attended on the average by about 50 Army and Navy officers and civilian scientists engaged in war research. They proved of the greatest utility in furthering progress through the interchange of ideas between the different research groups both here and abroad. At each meeting all of the reports received through the Research Information Service from the foreign research groups since the last meeting were briefly summarized and discussed and detailed discussion devoted to such reports as warranted it. Further, these meetings became a recognized place of report of officers of our own service returning from Europe on scientific and technical missions and also of officers of foreign governments connected with the various foreign war missions. To preserve the necessary secrecy the meetings were held under the authority of the Army and Navy Intelligence Services, and the group authorized to attend consisted of the official representatives of the various war missions, officers specially delegated each week by the chiefs of the bureaus of the Army and Navy, and some

30 civilian scientists, all of whom were passed upon by both the Army and Navy Intelligence Services. These meetings constituted one of the most effective war services rendered by the National Research Council, and had a marked effect in accelerating research and development projects and in pointing out useful new lines of endeavor. As the major part of the reports sent to this country through the scientific attachés in London, Paris, and Rome have dealt with subjects coming directly within the field of the Physics Division, Dr. F. C. Blake was later appointed by the executive committee of the Division to study thoroughly all appropriate material coming in from abroad, and to arrange for its full presentation before the weekly conference of the Physics and Engineering Divisions and its distribution to the proper research groups in this country. He also assisted the Research Information Service in obtaining reports for transmission abroad upon physical problems under investigation in the United States.

It is clear from its membership and plan of organization that the Physics Division, like the Research Council itself, is a federation of research groups both inside and outside the War and Navy Departments and the civil branches of the Government. Many of the researches initiated under its auspices, as, for example, that on the submarine problem, were undertaken before most of its members were connected with the Army and Navy Departments. As the war progressed the membership of the Division became more and more completely incorporated into the Army and Navy, and large funds from both of these sources became available for the continuation of the work. Thus, the chairman and vice chairman of the Division were placed, in the autumn of 1917, in charge of the Science and Research Division of the Signal Corps, which was organized by the Research Council at the request of the Chief Signal Officer. The original problem organization of the Physics Division has been maintained, and the executive committee of the Division has continued to discuss and to make recommendations upon the various problems initiated by its members, whether these problems have in their later stages been financed by Research Council funds or by funds of those branches of the Army and Navy with which the members of the Division were subsequently connected.

The problems considered by the Division may be grouped under nine heads, as follows:

A. Airplane instruments.

B. Bomb sight, bomb trajectory, and stabilization problems.

C. Photographic problems.

D. Signaling problems.

E. Detection problems.
F. General airplane problems.

G. Balloon problems.

H. Ordnance problems.

I. Miscellaneous problems.

Most of these were carried out under the Science and Research Division of the Signal Corps and the Bureau of Aircraft Production. It would be impossible within the limits of this report to discuss the details of the seventy-odd problems in which the Physics Division was directly or indirectly concerned. Moreover, in many cases it would be manifestly inappropriate to do so, partly because of the confidential character of the work and more particularly because certain investigations were carried out at the expense and under the immediate direction of a branch of the Army or Navy or some body other than the National Research Council.

The nature of the council as a federation of research activities, and the fact that its prime concern is in the accomplishment of an important result rather than in the precise mode of procedure by which that result is obtained, naturally made its functions in the study of war problems very diverse. In some instances its work was limited to the initiation of investigations, which were sooner or later taken over by some other agency of the Government well qualified, through the possession of available funds and the necessary means of research, to conduct them to successful conclusion. In other cases, where suitable Government agencies were not available, the Research Council not only organized extensive investigations but provided funds and even erected laboratories provided with special equipment for solving vitally important problems. In the Physics Division these and other modes of procedure were all abundantly illustrated, as a detailed history of the origin, primary organization, and development of each problem dealt with would render clearly apparent. In this brief mention of the report of the Physics Division we must content ourselves with some reference to certain problems of special significance, in which the Research Council, for one reason or another, was called upon to play a leading part.

Perhaps the most notable case in point is the submarine problem. The importance of devising means for the detection and destruction of submarines was clearly apparent long before the United States entered the war. The Bureau of Steam Engineering of the Navy Department was fully alive to the importance of the problem, and in conjunction with the bureau the General Electric Co., the Western Electric Co., and the Submarine Signal Co. attacked the question with vigor. The Naval Consulting Board also recognized fully the seriousness of the situation and organized investigations of a similar character. As for the National Research Council it was recognized from the outset that this question, like many other scientific investi

gations dealt with under peace conditions, called for international cooperation. Accordingly the council dispatched a scientific committee, under the chairmanship of Prof. Joseph S. Ames, to France and England at the very beginning of the war to gather information bearing upon military and naval problems, and to secure early and effective cooperation in dealing with them. The French Government cordially responded, and a strong group of scientific men, under the chairmanship of M. Fabry, familiar with all aspects of the research problems dealt with in France from the beginning of the war, was sent to the United States upon a return visit. The English and Italian men of science, with whom arrangements for cooperation had also been made, sent representatives, including Sir Ernest Rutherford and Commander Cyprian Bridge from England and Lieut. Giorgio Abetti from Italy, to join the French committee in the United States.

Soon after the arrival of these gentlemen in Washington the Research Council, acting in cooperation with the Navy Department, organized a conference on the entire submarine problem, in which representatives of the Navy Department, with physicists and engineers already engaged in the study of the problem, joined with the French and British representatives. The results of this conference indicated such large possibilities that a group of some 50 physicists and engineers were brought together by the Research Council for a second three-day conference. As a result of these conferences a large number of investigations, for the most part dealing with the problem of submarine detection, were organized by the Research Council in cooperation with the Special Board on Anti-Submarine Devices of the Navy, which had entire jurisdiction over all antisubmarine experimenting in this country. The board consisted of a number of naval officers representing various bureaus of the Navy, together with four civilian members, one of whom was the chairman of the Physics Division of the Research Council and chairman of its Anti-Submarine Committee. The greater part of the experimental work of the Special Board on Anti-Submarine Devices was done at the New London Experimental Station, at which members of the Committee on Submarine Investigations of the National Research Council began work in June, 1917. The work of the Station attained such success in its initial stages that the Navy Department provided ample funds for its maintenance and development, and its work was subsequently carried out on a large scale at New London and elsewhere. Besides appointing the nucleus of the scientific group organized at New London and providing for initial expenses of travel, etc., the Research Council established additional antisubmarine groups at New York, Madison, Wis., Chicago, and in connection with the submarine base at San Pedro, Calif.

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