least until the pressure of the upper atmosphere has become readjusted, they establish at the base of the stratosphere a layer of minimum temperature.

These conclusions are in full accord with Figs. 2 and 3.

Similarly, whatever the origin of the migratory cyclone, another of the many meteorological problems that needs further investigation, one of its chief features is a deep wind in its eastern portions from lower to higher latitudes. In this case the rotation of the earth leads to a speeding up of the eastward component of the velocity. Hence this air may be expected to run forward and up and thus to produce a low pressure to its rear. Because of the upward trend thus given to much of the air in the cyclone that portion of it below the stratosphere is more or less dynamically cooled. At the same time the stratosphere bodily drops to lower levels wherever air has been removed from beneath it. Hence its pressure is increased at every level in proportion to the initial pressure at that level and its temperature thereby raised by an equal amount throughout.

Radiation and absorption probably also have some part in determining the temperature conditions and interrelations of migrant cyclones and anticyclones, but the chief cause appears to be purely mechanical, as above explained.

THE LAW OF WIND-INCREASE WITH ELEVATION

The fact that wind-velocity generally increases with elevation has long been known, but the law of this increase was not formulated for any levels until only a few years ago, nor the cause back of this law revealed until still more recently. The law in question applies only to that portion of the atmosphere that lies between the elevations of 3 to 4 and 8 to 9 kilometers. Nor could it in any modified form be satisfactorily extended to other levels-not much below 3 kilometers, because of the irregular disturbances due to surface friction, innumerable barriers, and convectional turbulence; nor much beyond 9 kilometers, because not far from this level the vertical temperature gradient, upon which the

winds largely depend, rather abruptly and greatly changes. The form of this law, that applies as a first approximation to so much of the atmosphere, is very simple. It says merely that the velocity of the wind varies inversely with its density, or, in other words, that the mass-flow is a constant. This was determined empirically first by Clayton, of this country, who hid his discovery in a journal of small circulation; and subsequently by Egnell of France, whose proper publication won for the same discovery the appreciative name Egnell's law.

To show the rationale of this law it is convenient to assume the well known fact that the velocity of a steady wind half a kilometer or more above the surface and thus nearly frictionless, is given approximately (neglecting the generally small deflective force due to cyclonic motion) by the equation

G V= p2w sin p

in which G is the horizontal pressure gradient, or difference in pressure per unit distance normal, horizontally, to the local isobar, ρ density of the air, o the angular velocity of the earth's rotation and & the latitude. From this equation it follows at once that at any place, the mass-flow, pv, is directly proportional to the horizontal pressure gradient. Hence to find the relation of mass-flow to elevation it is sufficient to determine the relation of horizontal pressure gradient to elevation.

Consider, then, two adjacent columns of air initially exactly alike, and let the temperature of one be increased over that of the other by the same amount throughout. Each isobaric level in the warmed column will thereby be raised in direct proportion to its original height, and the horizontal pressure thus established at each height h will be proportional to the product of this lift by the local density. That is

G hp G' h'p'

But from the height of 3 or 4 kilometers above sea level up to that of 8 or 9, the density of the atmosphere is roughly inversely propor

SCIENTIFIC EVENTS

MEMORIAL TO LEWIS HENRY MORGAN

TEMPORARILY displayed in Memorial Hall, at the American Museum of Natural History, New York, is a bronze tablet commemorating the one hundredth anniversary of the birth of Lewis Henry Morgan, called the father of American anthropology. The tablet embodies an Iroquois Indian decorative motif and a wampum record of the founding of the "Iroquois League." After being exhibited at the American Museum, the tablet will be sent to Wells College, where it will be permanently installed.

Morgan was born in Aurora, New York, in 1818, and died in 1881 at Rochester. He graduated from Union College in 1840, and was admitted to the New York bar in 1842. In 1855, his interest in certain rich iron deposits led him to make practical explorations into northern Michigan, at that time a wilderness. Here he became interested in the habits and labors of the beaver, and after several years of observation and study wrote his "American Beaver and His Works," which is still considered the most authentic book of its kind.

Early in his life, Mr. Morgan had become a member of a secret society known as the Gordian Knot. This society was accustomed to meet on the ground of the ancient confederacy of the "five nations," holding its council fires at night on the former lands of the Mohawks, Oneidas, Onondages, Cayugas

and Senecas. Gradually its members developed a curiosity about the history, institutions and government of the Indians, and began to gather together odd scraps of information about them. Mr. Morgan's interest became so strong that he devoted himself to serious study of the subject. He wrote a number of papers which were read before the New York Historical Society and elsewhere, and some of which were published in book form in 1851 under the title of "The League of the Iroquois," in which the social organiation and government of the confederacy were thoroughly explained, the first scientific account of an Indian tribe. He later wrote a number of books and papers on Indian life, and gathered together a library containing many important works on American ethnology. For the purpose of studying the Six Nations, he organized the Grand Order of the Iroquois. He was assisted in his researches by the Smithsonian Institution and the United States Government.

The tablet at the American Museum was designed by Mr. Gohl, of Auburn. In addition to the symbolic decorations and various facts about Mr. Morgan's life and works inscribed on the tablet, is the following quotation from his "Ancient Society": "Democracy in Government, Brotherhood in Society, Equality in Rights and Privileges and Universal Education foreshadow the Next Higher Plane of Society to Which Experience, Intelligence and Knowledge are Steadily Tending. It will be a Revival in a Higher Form of the Liberty, Equality and Fraternity of the Ancient Gentes."

THE BRITISH DYE INDUSTRY1

THE works and appliances of the German firms remain substantially undiminished in extent and unimpaired as to organization, while they still possess a large body of expert chemists and engineers fully acquainted with the details of the business, though doubtless there have been serious losses in the course of the war. It is, however, satisfactory to learn from the address of Lord Armaghdale,

1 From Nature.

the chairman of Levinstein's, that, in his opinion, provided sufficient financial support is forthcoming, this country may be rendered independent of German dyestuffs. On the scientific side, he added, success is certain. There is in this country a larger amount of chemical talent than has hitherto been recognized, and during the war many university professors and others occupied with purely scientific research have given valuable assistance to the color industry, as well as in other departments of manufacture.

Considering the difficulties to be overcome in the revival of chemical industries in this country at the beginning of the war, and, as compared with Germany, the serious lack of organization and of scientifically trained assistance, the success so far achieved is encouraging in the highest degree. There is no justification for the gloomy view of the situation sometimes taken, and if the scheme now working under the Board of Trade is not perfect, it is, at any rate, a step in the right direction, and has been accepted by the dyemakers and the dye-users.

The trade and licensing committee referred to in the scheme has now been constituted under Lord Colwyn as chairman. The following are the other members: Mr. Henry Allen, Mr. Milton Sharp and Mr. Lennox B. Lee, nominated by the Color Users' Committee; Mr. T. Taylor, representing the paint and varnish manufacturers; Dr. Herbert Levinstein and Mr. J. Turner, nominated jointly by British Dyes, Ltd., and Levinstein's, Ltd.; Mr. W. J. Uglow Woolcock, M. P., nominated by the Association of British Chemical Manufacturers; and Mr. W. H. Dawson, nominated by the president of the Board of Trade. The commissioner for dyes, Sir Evan Jones, M.P., will be an ex officio member without a vote. Dr. H. Levinstein is the well-known managing director of Levinstein's, Ltd., and he will control the scientific and manufacturing operations of the new corporation resulting from the fusion of British Dyes and Levinstein's. Mr. J. Turner has been a director of British Dyes, Ltd., for several years, and he

will be largely influential in the business arrangements of the conjoint firms.

The functions of the committee now constituted will be to determine the colors and intermediates which shall be licensed for import into the United Kingdom after the conclusion of peace, and to advise the Commissioner for Dyes as to the colors and intermediates the manufacture of which in this country should be specially encouraged.

It is satisfactory to find that the Port Ellesmere indigo factory has been in full work for some time, and that land has been secured for considerable extensions of the works in the near future.

SCIENTIFIC NOTES AND NEWS

THE gold medal of the National Institute of Social Sciences has been awarded to Dr. Wm. H. Welch, of the Johns Hopkins Medical School.

DR. HENRY A. BUMSTEAD, professor of physics at Yale University, has returned from France, having been engaged in war work abroad since 1917.

DR. LAFAYETTE B. MENDEL, professor of physiological chemistry in Yale University, who has been overseas as a representative of the U. S. Food Administration on the InterAllied Scientific Food Commission, has returned to the United States.

MAJOR GENERAL WILLIAM C. GORGAS, U. S. Army, retired, will return from Guatemala to Washington, D. C., in February, and on his return to South America in the spring will be accompanied by Mrs. Gorgas.

COLONEL G. A. BURRELL, of the Chemical Warfare Service, returned to private chemical engineering work at Pittsburgh in January. He was called to Washington by the Bureau of Mines early in the war, to take charge of the research organization that later became the American University Experiment Station of the Chemical Warfare Service.

Ar the recent meeting of the Mathematical Association of America Professor Herbert Ellsworth Slaught, of the University of Chicago, was elected president.

FRED RASMUSSEN, professor of dairy husbandry, The Pennsylvania State College, State College, Pa., was, on January 21, 1919, appointed secretary of agriculture for the state of Pennsylvania and left immediately to take up his new duties at Harrisburg.

CARL N. AUSTIN, who went from the SearsRoebuck laboratories with a commission as first lieutenant in Gas Defense, has recently been appointed director of the First Corps Gas School located at Gondrecourt, Meuse, France.

LIEUTENANT JOHN P. TRICKEY, a member of the Chicago Section of the American Chemical Society, has been promoted to a captaincy in the Chemical Warfare Service, and is on duty in France.

DR. KEIVIN BURNS, of the division of optics, Bureau of Standards, is absent on an extended trip abroad in connection with his scientific work.

THE Geological Society, London, has made its awards as follows: Wollaston medal, Sir Aubrey Strahan, director of the British Geological Survey; Murchison medal, Miss Gertrude L. Elles, Newnham College, Cambridge; Lyell medal, Dr. W. F. Hume, director of the Geological Survey of Egypt; Bigsby medal, Sir Douglas Mawson; Wollaston fund, Dr. Alexander Logie Du Toit, Geological Survey of South Africa; Murchison fund, Mrs. Eleanor M. Reid; Lyell fund, Mr. John Pringle, Geological Survey of England and Wales, and Dr. Stanley Smith, University College, Aberystwyth.