460 REVIEWS

The dedication points out that the receipt of contributions from all over the world for this special number indicates the respect for the scientific work of the Institute and of Profs. Conrad and Ficker.

The volume includes 23 papers from authors in several European countries, the U.S.A. and India. The subjects dealt with include radiation, surface and upper-air climatology, bioclimatology, meteorological effects in disease, evaporation, climatic change, and glaciology.

Only a few papers can be mentioned individually. Albrecht and Goldschmidt each describe observations of total radiation from a cloudless sky and discuss formulae for the relation between the radiation and the altitude of the sun and with cloudiness. Flohn discusses the mechanism of the occurrence of westerly winds near the Equator and Reinhard the upper wind observations made by radar on the continental coast of the English channel during the war. Ramdas gives a valuable survey of the investigations at Poona into the meteorology of the lowest few feet of the atmosphere; this paper contains much information on temperature, humidity and wind gradients, on the heat loss from the surface by convection and on the temperature and humidity in various kinds of crop. Ekhart provides a comprehensive climatological study of 50 years' wind observations at Vienna.

Thornthwaite describes a method of measuring evapotranspiration and some calculations of the potential evapotranspiration for different climates, and Lauscher the worldwide distribution of Hill's cooling power. In one of the papers on meteorological effects in disease Berg produces statistics to show that occurrences of lung embolism are not associated with passage of fronts. Prohaska produces evidence that the Antarctic has not experienced any increase of mean temperature such as has occurred over much of the Arctic since the early years of the present century and Winter examines the secular variations of the summer temperature of Vienna with 25-year overlapping means compiled from the 175-year-long series of observations; the values, dated from the last year of the period, were high in the first thirty and last thirty years of the 19th century, fell after 1900 and are now rising again.

G.A.B.

Archiu fur Meteorologie, Geophysik und Bioklimatologie, Serie A, Bd. IV. Vienna (Springer), 1951. Pp. 448; Figs., tables. DM.65.

Volume IV, Series A, which is also a special number, contains 31 papers, all of them substantial ones, in its 448 pages. Their subjects include tropical cyclones, theory of water-spouts and tornadoes, gravity waves in the atmosphere, lag in radiosondes, solar effects on the frequency of formation of depressions, dynamics of jet streams, formation of ice crystals in the atmosphere, electric conductivity of the air near the ground, electric currents in the ionosphere, changes in ozone amount associated with sudden ionospheric disturbances, methods of statistical and harmonic analysis in geophysics, atmospheric thermodynamics, turbulence, and seismology.

Again only a few papers can be mentioned individually. H. Koschrnieder reviews theories of formation of dust devils and tornadoes and has a detailed analysis with good photographs of a dust devil in process of formation; he regards dust devils as whirls set off as air flows past the edges of obstacles and so accounts for the high proportion of anticyclonically rotating ones and calculates some pressure falls for tornadoes on the basis that the pressure in the centre is at most the same as at the cloud base. W. Bleeker and A. Delver give a new theory of the formation of tornadoes on the basis of the temperature differences between the areas with heavy rain and those without. C.-G. Rossby, in a mathematical paper, explains the formation of jet streams on the basis that stratified air currents assume that distribution of wind velocity with height which corresponds to a minimum value of rate of momentum transfer in the vertical. D. P. McIntyre outlines the main principles of the Chicago school of meteorology and of its leading spirit C.-G. Rossby as devotion to study of the hydrodynamics of the field of flow rather than of pressure. There are two British contributors: Prof. S. Chapman and Dr. R. S. Scorer. Prof. Chapman introduces a new term into ionospheric physics with his equatorial electro-jet ' which is an intense electric current flowing eastwards over the sunlit equator invoked to explain the large diurnal range in the horizontal magnetic force at Huancayo and other equatorial observatories. Dr. Scorer outlines his mathematical theory of gravity-waves in the atmosphere and discusses in detail the circumstances in which the waves can be formed.

May we add our congratulations to the Austrian Central Institute and our best wishes for its second century ?

G.A.B.

Berichte des Deutschen Wetterdienstes in der U.S. Zone, No. 42,1952. Pp. 463; Figs., tables, charts. DM.50.

This number of the series of Berichte of the meteorological service of the U.S. Zone of Germany is dedicated to the well-known climatologist Prof. Dr. K. Knoch on his 70th birthday. The volume contains 107 papers, many very short, in its 463 pages.

The subject range is wide; a rough classification list is clirnatolopy, bioclimatology, micrometeorology, phenology, agricultural meteorology, radiation, instruments, meteorological factors in health and disease, upper air climatology, meteorological organization.

Taking a few papers almost at random: Dr. K. Keil gives an interesting article on the development of the Library of the US. Zone service from its first foundation in 1886 as the Library of the Prussian State