13. A report from Dean Roscoe Pound, of the Law School of Harvard University, concerning the legal requirements of the laws of Massachusetts for corporations such as the American Association for the Advancement of Science, was read and the executive committee expressed its hearty thanks to Dean Pound for help in this regard. Dean Pound states that he sees no reason for fear that the association is not carrying on business entirely in accord with the laws of Massachusetts.

14. It was voted that any affiliated society having two representatives in the council of the association may, if it so desires, name one of its council representatives to be an ex-officio member of one section committee and the other to be an ex-officio member of another section committee. The wishes of the affiliated societies are to be followed in this. An affiliated society having but one representative in the association council may determine in which section committee its representative is to be an ex-officio member.

15. Dr. Kellogg spoke of the use of advertising in the general programs of the British Association for the Advancement of Science and the executive committee approved of the proposal to introduce advertising in the general program of the Kansas City meeting.

The evening session convened at 8:00, with Dr. Cattell in the chair and the following members present: Cattell, Fairchild, Humphreys, Livingston, Noyes, Ward.

16. It was voted to transfer the Gamma Alpha Graduate Scientific Fraternity from the group of affiliated organizations to the group of associated organizations, since the nature of the fraternity makes it belong to the broader rather than to the more restricted group. It is related to the association as a whole.

17. The Institute of Radio Engineers was elected to official affiliation with the association.

18. The Phi Sigma Biological Research Society was elected to official affiliation with the association.

19. Dr. Ward reported on the Boulder and Portland meeting. His report was accepted with thanks.

20. The executive committee adopted the following resolution on the National Parks system and directed the permanent secretary to transmit copies of it to Secretary Work and Mr. Robert Sterling Yard.

Resolved, that the executive committee of the American Association for the Advancement of Science, at its regular fall meeting held in Washington on October 25, 1925, heartily approves the Secretary of the Interior's promotion of education to a place of first importance in the administration of the National Parks System, and his purpose to eliminate from the system any parks that tend to reduce its effectiveness as a great natural museum and a supreme expression of beauty and majesty and truth in nature.

21. Major H. S. Kimberly, of Washington, was invited to present plans for handling the exhibition at the Kansas City meeting and he was introduced at 8:30. After full discussion the executive committee approved an arrangement with Major Kimberly by which he is to be manager of the Kansas City exhibition under the

authority of the permanent secretary. He is to proceed to secure exhibits from firms and to make all necessary arrangements at Kansas City, not only for exhibits of a commercial character but also for such exhibits from individual scientists and scientific institutions and laboratories as may be secured. The manager of the exhibition is to prepare and arrange for the printing of a catalog of the exhibition. He is also to arrange for and secure advertising from firms, for use in the general program of the Kansas City meeting. It is planned that the exhibition at Kansas City will be much larger and more important and better arranged than any previous exhibition held by the association and that it will be self-supporting. Exhibits by individual scientists are cordially invited and will be entered without charge. A small charge will be made for commercial exhibits, to defray the costs of the exhibition arrangements. Correspondence regarding prospective exhibits should be addressed to the Manager of the Kansas City Exhibition, American Association for the Advancement of Science, Smithsonian Institution Building, Washington, D. C.

22. Some consideration was given to the possibility of the association taking part in a great exhibition of science progress, to be held in New York City next year. A committee was named to consider this proposal further and to report to the executive committee at the Kansas City meeting. The committee consists of Drs. J. McK. Cattell, M. I. Pupin, Simon Flexner and Henry Fairfield Osborn.

23. President Pupin was named to represent the association on the Board of the National Museum of Engineering and Industry.

24. The permanent secretary reported that a member of the association is interested in getting its friends to include the association in their wills, leaving bequests for its use. The executive committee expressed its appreciative approval of this effort and will be glad to aid in that direction.

25. It was voted that a charge of fifty cents be made at the Kansas City meeting, as a ticket endorsement and validation fee, the funds thus secured being used to help defray the extra expenses of the meeting.

26. It was voted that each registrant at the Kansas City meeting is to receive one free copy of the general program and that extra copies may be purchased at a price of fifty cents.

27. The executive committee approved the plan to have a series of popular lectures at the Kansas City meeting,

a number of them in the afternoon. These are to be planned for the general public rather than for professional scientific workers.

28. It was voted that arrangements for the Kansas City meeting not otherwise cared for are to be left in the hands of the permanent secretary.

The executive committee adjourned at 11 o'clock, to meet at the Hotel Muehlebach, in Kansas City, at 10 a. m., on Monday, December 28.

BURTON E. LIVINGSTON, Permanent Secretary

The Institute for the Study of the History of Civilization; The Peking Society of Natural History; Field Meeting of the Association of Ameri can State Geologists; Lectures on Mental Hygiene at the New York Academy of Medicine..

Scientific Notes and News

University and Educational Notes

Discussion and Correspondence:

A Plan for the Promotion of Small Museums: LAURENCE VAIL COLEMAN. Evidence of Human Artifacts in the American Pleistocene: HAROLD J. Cook. Eggs Supposed to be Luminous: A. H. GODBEY. The Conservation of Beaver by an Indian: DR. HARLAN I. SMITH. André Parmentier and the Brooklyn Botanic Garden: DR. C. STUART GAGER

Quotations:

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HIGH FREQUENCY RAYS OF
COSMIC ORIGIN1

It was as early as 1903 that the British physicists, Rutherford and McLennan, noticed that the rate of leakage of an electric charge from an electroscope within an air-tight metal chamber could be reduced by enclosing the chamber within a completely encircling metal shield or box with walls a centimeter or more thick. This meant that the loss of charge of the enclosed electroscope was not due to imperfectly insulating supports, but must rather be due to some highly penetrating rays, like the gamma rays of radium, which could pass through metal walls as much as a centimeter thick and ionize the gas inside.

In view of this property of passing through relatively thick metal walls in measurable quantity, the radiation thus brought to light was called the "penetrating radiation" of the atmosphere, and was at first quite naturally attributed to radioactive materials in the earth. But in 1910 and 1911, it was found that it did not decrease as rapidly with altitude as it should upon this hypothesis. The first significant report upon this point was made by a German physicist, Gockel, who took an enclosed electroscope up in a balloon with him to a height of 13,000 feet and reported that he found the "penetrating radiation" about as large at this altitude as at the earth's surface, despite the fact that Professor Eve, of McGill University, had calculated that it ought to have fallen to half its surface value in going up 250 feet.

In 1912, 1913 and 1914, two other German physicists, Hess and Kohlhorster, repeated these balloonmeasurements of Gockel's, the latter going to a height of 9 km., or 5.6 miles, and reported that they found this radiation decreasing a trifle for the first two miles and then increasing until it reached a value at 9 km., according to Kohlhorster's measurements, eight times as great as at the surface. This seemed to indicate that the penetrating rays came from outside the earth, and were therefore of some sort of cosmic origin. The war put a stop the world over to further studies of this sort, but as soon as we could get the proper instruments built after the war in the newly equipped Norman Bridge Laboratory of Physics, I. S. Bowen and myself went to Kelly Field, near San Antonio, Texas, with four little recording electroscopes which we succeeded in the spring of 1922 in

1 Read to the National Academy of Sciences, Madison, November 9, 1925. Copyright, 1925, by Science Service, Inc.

sending up in sounding balloons to almost twice the heights which had previously been attained. The highest flight reached the altitude of 15.6 km., or nearly 10 miles.

These instruments were interesting in that, though they were built to hold 300 cubic centimeters of air at 150 pounds pressure, and were provided each with a recording barometer, thermometer and electroscope, also with three different sets of moving photographic films and the necessary driving mechanism, the total weight of the whole instrument was yet but 180 grams, or about 7 ounces.

In these experiments we expected, if the results previously reported were correct, to find very large rates of discharge; for our instruments went up to such heights that nine tenths of the atmosphere had been left beneath them, and only one tenth was left to cut down, by its absorption, the intensity of the hypothetical rays entering from outside. The results were contrary to this expectation. They proved conclusively, however, in agreement with the observations of Hess and Kohlhorster, that the penetrating radiation was greater at great altitudes than at the surface, but that the amount of the increase was not more than a fourth of that predicted from the results of the German observers. (Two years later they reduced their estimates, after further experiments, so that they were no longer in conflict with our measurements.)

Since the origin of the rays was still uncertain, with indications in favor of some cosmic source, Mr. Russell Otis and myself felt that the next step was to find out how penetrating the rays were; and since they were weaker at the surface than higher up we went to the top of Pike's Peak in the summer of 1923, carrying up 300 pounds of lead and a big 6 x 6 x 6-foot water tank for the sake of making absorption measurements on such rays as were found at that altitude.

We found that though our electroscopes discharged twice as fast on Pike's Peak as at the altitude of Pasadena, the rays were cut down so fast by our absorbing screens that it was certain that the greater part of them were not much if any more penetrating than the ordinary gamma rays emitted by radium. We found, further, that the rate of discharge of our electroscope was decreased by ten per cent. by a heavy snow storm which occurred during the week in which we were on the peak. This showed conclusively that the chief part, at least, of the rays with which we were experimenting on the peak were of local origin, and that they might be due to radioactive matter which in some unknown way got into the upper regions of the atmosphere.

The search for the cause of the increase with altitude in the intensity of these soft gamma-like rays became, therefore, quite as interesting as the question

of the existence of a very penetrating radiation of cosmic origin, since this latter would produce at the most but a fraction, and no large fraction either, of the observed increase between Pasadena and Pike's Peak. Mr. Harvey Cameron and I therefore planned experiments for the summer of 1925 which were designed (1) to settle definitely the question of the existence or non-existence of a small, very penetrating radiation of cosmic origin, and (2) to throw light on the cause of the variation with altitude of the softer radiation of the gamma ray type which we had found more than twice as intense on Pike's Peak as at Pasadena.

To bring to light the very penetrating radiation, if it existed, it was necessary to find at very high altitudes very deep snow-fed lakes, for any radioactive contamination of the water through its seepage through the earth would vitiate the results obtained by sinking electroscopes to different depths beneath the surface of the lake.

We chose for the first experiment Muir Lake (11,800 feet high), a beautiful body of water hundreds of feet deep just under the brow of Mount Whitney, the highest peak in the United States. Here we worked for the last ten days in August, sinking our electroscopes to various depths down to 60 feet. Our experiments brought to light altogether unambiguously a cosmic radiation of such extraordinary penetrating power that the electroscope reading kept decreasing down to a depth of 45 feet below the surface. The atmosphere above the lake was equivalent in absorbing power to 23 feet of water, so that we had found rays, coming into the earth from outer space, so penetrating that they could pass through 45 plus 23, equalling 68 feet of water or the equivalent of 6 feet of lead, before being completely absorbed. This represents rays much harder (more penetrating) than any which had before even been imagined.

The most penetrating X-rays which we produce in our hospitals can not go through half an inch of lead. Here were rays originating somewhere out in space, at least a hundred times more penetrating than these.

Further, high penetrating power means, according to modern physics, simply high frequency or short wave-length. Our experiments indicate, then, that there is a region of frequencies as far up above the X-ray frequencies as are these latter above the frequencies of light waves.

They show quite definitely, too, that these highest frequency rays are not homogeneous, but have a measurable spectral distribution, the shortest waves which we observed being a little less than twice the frequency of the longest, for the rays which we actually observed in Muir Lake changed hardness or frequency as they were filtered through greater and greater

thicknesses of water, just as X-rays are successively hardened by passing through successive layers of lead. The experiments with the sounding balloons indicates that the frequencies of these cosmic rays do not extend 1 over into the X-ray region of frequencies, else we should have obtained larger discharges in the experiments with sounding balloons when nine tenths of the atmosphere had been left beneath us.

Further, we obtained good evidence that these cosmic rays shoot through space in all directions, this evidence being found in the fact that we could observe no change whatever in their intensity throughout day or night.

All the results obtained in Muir Lake were checked with wonderful completeness by another set of observations in another snow-fed lake-Arrowhead Lake -300 miles away from Muir, 7,000 feet lower, and equally deep, where the Arrowhead Lake Development Company kindly put all their facilities at our disposal. Indeed, the absorbing power of the atmosphere between the elevations of Muir and Arrowhead lakes is the equivalent of about two meters of water, and as a matter of fact every reading in Arrowhead was practically identical with one taken in Muir at a depth two meters lower.

We can draw some fairly reliable conclusions as to the origin of these very penetrating and very high frequency rays. The most penetrating rays that we have known anything about thus far, the gamma rays of radium and thorium, are produced only by nuclear transformations within atoms. This means that they are produced by the change of one atom over into another atom, or by the creation of a new type of atom. It is scarcely possible then, to avoid the conclusion that these still more penetrating rays which we have here been studying are produced similarly by nuclear transformations of some sort. But these transformations must be enormously more energetic than are those taking place in any radioactive changes which we know anything about. For the frequency of any emitted ray is, according to our present knowledge, proportional to the energy of the subatomic change which gives birth to it. We can scarcely avoid the conclusion, then, that nuclear changes having an energy value perhaps fifty times as great as the energy changes involved in observed radioactive processes are taking place all through space, and that signals of these changes are being sent to us in these high frequency rays.

The energy of the nuclear change which corresponds to the formation of helium out of hydrogen is known, and from it we have computed the corresponding frequency and found it to correspond closely to the highest frequency rays which we have observed this sumThe computed frequencies of these rays also

mer.

correspond closely to the energy involved in the simple capture of an electron by a positive nucleus. It is possible that this phenomenon is actually going on all through space. This is I think the most probable source of these rays. It is true that the formula underlying this computation of the frequencies of these rays from their absorption coefficient is of uncertain validity. It is a formula, nevertheless, that works well in the frequency range in which we can get independent checks upon it, namely in that of the X-ray field and the gamma ray field.

According to this formula the wave length of the shortest waves which we have here investigated is .0004 Angstroms, or but one fiftieth of that of the hardest gamma rays heretofore known, and but one ten millionth that of ordinary light. The longest wave length which we have found is about five thirds of the shortest, or .00067 Angstroms.

When these extraordinarily high frequency rays strike the earth, according to the now well-established Compton effect, they should be transformed partially into soft scattered rays of just about the hardness, or the wave length, of the soft rays which we have actually observed on Pike's Peak and Mount Whitney. The reason these soft rays were more plentiful on the mountain peaks than at Pasadena would then be found simply in the fact that there are more than twice as many of the hard rays to be transformed at the altitudes of the peaks than at that of Pasadena. This seems to be the solution of the second of our summer's problems.

But how can nuclear transformation, such, for example, as the formation of helium out of hydrogen or the capture of an electron by a positive nucleus, be going on all through space, the resulting rays coming apparently as much from one direction as from any other, and certainly not a whit more plentifully from the direction of the sun than from that diametrically opposite to it, as evidenced by the entire equality of our midday and midnight observations? The difficulty is not so insuperable, in view of the transparency even of large amounts of matter for these hard rays, combined with Hubble's recent proof at the Mount Wilson Observatory that some of the spiral nebulae are at least a million light years away. The centers at which these nuclear changes are taking place would then only have to occur at extraordinarily widely scattered intervals to produce the intensity of the radiation observed at Muir Lake.

The only alternative hypothesis to that above presented, of high frequency rays traversing space in all directions, might seem to be to assume that the observed rays are generated in the upper layers of the atmosphere by electrons shooting through space in all

directions with practically the speed of light. This hypothesis might help in interpreting the mysterious fact of the maintenance of the earth's negative charge, but it meets with insuperable obstacles, I think, in explaining quantitatively the variation with altitude of the ionization in closed vessels. In any case, this hypothesis is, in its most important aspect, very much like the one represented above, for it, too, fills space with rays of one sort or another travelling in all directions with the speed of light. From some such conception as this there now seems to be no escape. And yet it is a conception which is almost too powerful a stimulus to the imagination. Professor MacMillan, of Chicago, will wish to see in it evidence for the condensation into matter out somewhere in space of the light and heat continually being radiated into space by the sun and stars, and the psychists will be explaining all kinds of telepathic phenomena by it.

In any event, our experiments seem to point to the following conclusions: (1) That these extraordinarily penetrating rays exist; (2) that their mass absorption coefficient may be as high as .18 per meter of water; (3) that they are not homogeneous, but are distributed through a spectral region far up above X-ray frequencies-probably 1,000 times the mean frequencies of X-rays; (4) that these hard rays stimulate, upon striking matter, softer rays of about the frequency predicted by the theory of the Compton effect; (5) that these rays come into the earth with equal intensity day and night and at all hours of the day or night, and with practically the same intensity

in all directions.

ROBERT ANDREWS MILLIKAN NORMAN BRIDGE LABORATORY OF PHYSICS, CALIFORNIA INSTITUTE OF TECHNOLOGY

COORDINATION OF THE HEALTH ACTIVITIES OF THE FEDERAL GOVERNMENT1

THE government machine, like the human mechanism, requires an occasional physical inventory. Such a health examination is in fact now being performed on our national government and is producing some interesting results. Just as a human appraisal, made by a doctor of medicine, frequently brings out latent physical impairments, so too this survey of governmental health functions, made by doctors of political science and of public health, discloses many administrative defects. Just as health examinations of individuals, now so strenuously advocated by physicians and sanitarians, usually indicate possibilities for

1 Read before Medical Section, Southwestern Division, American Association for the Advancement of Science, Boulder, Colorado, June 10, 1925.

physical improvements, so too this political inspection points the way to the desirability of a more effective centralization or correlation of the public health and medical activities of the government of the United States.

The promotion of national vitality is conceded to be one of the principal interests of any sovereignty. In the United States the care of the public health is, under our form of government, vested primarily in the individual states as a part of their police power. The federal establishment does, however, have certain legitimate public health activities, sanctioned by the Constitution and imposed by Congress under that authority. These duties include the power over interstate matters, involving the prevention of the spread of disease from one state to another; a similar power of foreign quarantine, that is, prevention of the introduction of disease from without; the control of the health of the people of federal territories and reservations; health powers incidental to taxation; public health matters involved in treaties; and, finally, scientific research, popular health instruction and cooperation and counsel for state and local health authorities on request.

All these duties are now exercised by the national government without in any way conflicting with state autonomy in public health matters. Of the hundred or more major administrative units of the federal service, at least thirty bureaus, divisions or other branches of the government are concerned directly or indirectly with some phase of the public health. In many instances, of course, the health work may be only incidental to other more important functions, or the health activities may constitute a relatively minor issue. Only eight of these thirty bureaus may be said to carry on health duties as their major object. These eight bureaus are, nevertheless, located in five different executive departments, and all the health activities of the government are scattered throughout the ten cabinet departments and a number of independent establishments.

The eight government bureaus or divisions whose public health activities may be said to be of major scope are as follows:

Public Health Service, Treasury Department.
Children's Bureau, Department of Labor.

Medical Division, Office of Indian Affairs, Department of the Interior.

Division of School Hygiene, Bureau of Education, Department of the Interior.

Division of Vital Statistics, Bureau of the Census, Department of Commerce.

Bureau of Chemistry, Department of Agriculture. Bureau of Home Economics, Department of Agricul ture.