The meteorologists of the Egyptian survey have contributed both to our knowledge of 

 the climate of the country and to various problems of dynamic meteorology. Regular 

 observations of the heat received from the sun have been made since 1907 with the Angstrom 

 pyrheliometer and with the electric recorder of Callendar. Free air observations with kites, 

 pilot balloons and captive balloons have also been prosecuted. The depth of the surface 

 trade winds in lower regions and the character of the layers of air next above, up to 5,000 

 metres, have also been studied. The intermediate calm surface or transition surface, or the 

 glide surface of Sandstrom, sometimes has a very steep inclination and sharp definition. In 

 Fact this glide surface, studied so carefully by Sandstrom in Norway, is undoubtedly a 

 characteristic of the atmosphere in all parts of the world. 



The late Dr. Rotch, by the use of kites and sounding balloons, studied the upper air at 

 Blue Hill Observatory, Hyde Park, Mass, and in the central region of the Mississippi 

 Valley. Up to 1,000 metres altitude there are many variations of pressure and temperature, 

 but above this there is a steady diminution of temperature and increase of velocity, except 

 that at 4,000 metres there is a rather sudden increase of velocity. 



The behaviour of the winds in the trade region has been the subject of special studies by 

 Mey, Campbell-Hepworth, Shaw, and of balloon observations by Hergesell, Rotch and 

 Teisserenc de Bort, to which must be added the work by Dynes and Shaw on the anemometer 

 records at St. Helena, and the work of Gold on the connection between air pressure and 

 periodic variations of the wind. The studies of Wegener and Stoll on the trade winds in the 

 neighbourhood of Teneriffe show that there are great irregularities produced by the presence 

 of this island, and the same must be true of the island of St. Helena, therefore the study 

 of the free trade winds in the open portions of the North and South Atlantic Oceans is espe- 

 cially needed. 



Wagner~shows that the isothermal layer is higher above an anticyclone and lower above 

 the cyclone, the difference amounting to 3,000 metres. The isothermal layer above a cyclone 

 is colder than above the anticyclone by ten degrees. 



Auroras. In February and March 1910 Prof. Dr. Carl Stoermer was able to carry out 

 satisfactorily the first precise simultaneous measures of the parallax and location of the 

 beams and arches of auroral light. He accomplished this by making simultaneous photo- 

 graphs of the auroras and the brighter stars at stations a few kilometres apart connected by 

 telephone. The general result is that out of 150 well determined altitudes the lowest cases 

 of auroral light occur at about 40 kilometres altitude, thus showing that the solar corpuscles 

 striking the earth's atmosphere penetrate far deeper than do the beta rays from radium. 

 The upper limit of these 150 cases was at 260 kilometres, with several cases occurring sporad- 

 ically above this, showing that the study of our atmosphere and its fields of force, with its 

 thermal and dynamic phenomena, must be extended outward to at least that altitude, or 

 one tenth of the earth's radius. 



Aerolites. The study of the upper air by means of twilight phenomena and auroras is 

 closely connected with its study by means of shooting stars and aerolites. A very complete 

 summary of OUT knowledge of these bodies is given by Von Niessl of Vienna in Vol. vi of 

 the Encycl. Math. Wiss., from which several facts are deduced bearing on the upper air. 

 Out of 49 altitudes of August meteors or Perseids the average appearance began at 115 kilo- 

 metres and disappearance occurred at 88 kilometres. In the same way H. A. Newton found 

 39 : meteors beginning at the average altitude 112 kil. and disappearing at 90 kil. Of the 

 November shooting stars or Leonids 78 began at 155 and ended at 98 kil. Out of 159 

 miscellaneous shooting stars the average beginning was at |io8 kil. and the disappearance at 

 86 kil. The average appearance of 121 large aerolites was at 138.6 kil. and the average 

 disappearance of 213 large ones was at 49.7 kil. The altitudes of first visibility, namely 

 from 108 kil. to 155 kil., are of course smaller for larger meteors than for the small molecular 

 masses involved in the aurora which may begin visibility at 260 kil., because of the smaller 

 geocentric velocities of the heavy meteoric masses, whose average velocity is but 72 kil. per 

 second, compared with that of electrons moving with the velocity of light. Evidently 

 the total diurnal heat communicated to the earth's upper atmosphere by shooting stars must 

 be a small but appreciable percentage of that absorbed directly by the air from the sunshine, 

 even if it be inappreciable compared with that received from the sun by the earth's surface. 



Climatology. The influence of climate on our physical condition, or the psychophysics of 

 climate, is. a study to which special attention has been given by Prof. Titchener of Cornell 

 and by Lehmann and Pettersen of Germany. The influence of climate on the nervous 

 system is very pronounced, quite as much so as the influence of food, drink, companionship, 

 or habitation in forests, among mountains or on islands in the ocean. 



Arctowski maintains that the compensations in the annual changes of cold and warm, 

 drought and flood, do not balance each other perfectly year after year, but experience irregu- 

 larities that must be charged to sudden changes in the solar radiation. 



The diurnal variation of the direction and strength of the wind in the Adriatic Sea has 

 Ixjen analysed by Mazelle. The bora is defined as a wind of 50 kilometres per hour or over. 

 On days. of such'boras the maximum wind velocity occurs at 9 A.M. and the minimum at 

 P.M. On the scirocco days the maximum velocity of wind occurs at midday and a second 



