"3 



maximum at 6 P.M., with a minimum at I A.M. During the bora the morning maximum 

 occurs at 10 A.M. at Trieste, but at 9 A.M. at Porer and at 8 A.M. at Lesina. On the scirocco 

 days the principal maximum occurs at noon at Porer, but at i P.M. at Lesina, and this retarda- 

 tion of one hour also occurs in case of the I A,M. minimum. The greatest duration of a bora 

 storm averaged 6.6 days at Porer in January. The greatest duration of the scirocco was 2.6 

 days in February. The strongest wind recorded during the 5 years, 1903-07, was 123 

 kilometres per hour, viz. for the bora of January 1906. 



Temperature of the Globe. The average temperature of ideal hemispheres of land or of 

 water, and of the whole globe, which has been the subject of many theories sinoe r the days of 

 Forbes, has recently been discussed by Liznar with the latest data from distant portions of 

 the globe. He finds that the average temperature of a land hemisphere would be 16.99 

 and of water hemisphere 13.27; a difference that is much less than that found by Spitaler. 

 He finds that a change of solar constant by one per cent would have a considerable change 

 in the temperature of each zone the change being greatest at the equator. An equal effect 

 would have been produced by a general change in the transparency of the stin's atmosphere, 

 or in the sun's temperature, or by local changes in the temperature or the transparency of the 

 sun's surface or of the earth's atmosphere. 



Secular Change of Climate. The variability, of temperature and the evaporation of 

 moisture in the dry regions of South Africa have been studied by J. R. Sutton. The relation 

 of desert plants to soil moisture in the dry regions of Arizona has been studied by R. E. 

 Livingston. The secular changes going on in the climates of various parts of the earth con- 

 tinue to attract both observers and theorists; most enthusiastic among these is Dr. Ellsworth 

 Huntington of Yale University. His former studies in Asia, Minor, Syria and Persia are 

 now being supplemented by extensive explorations in the arid regions of America. He 

 maintains his discovery of different periods of droughts and floods in ancient days in every 

 country; some of these were undoubtedly followed by extensive national migrations and 

 international wars. Dr. Huntington has even announced as a preliminary result of his 

 study of the annual rings of growth of large trees, that precision can be given to the dates of 

 the periods of drought. 



With reference to the analogous phenomena of glaciation, Dr. Julius Hann, in his address 

 at Innsbruck September 1905, remarked: " In connection with the many traces and observa- 

 tions of a progressive drying of Africa and the interior of Asia We have before us one of the 

 greatest problems of terrestrial physics. This problem seems all the more difficult to solve 

 since there are similar phenomena on a small scale that we may study completely as to time 

 and space, and yet are completely powerless to explain them from a meteorological point of 

 view: e.g. the progressive continued retreat of the Alpine glaciers that can be easily observed. 

 Although this phenomenon is going on in a region from which it would seem that sufficient 

 observations have continued for years, still it is not as yet possible to prove any direct con- 

 nection between these variations and the variations of the meteorological elements. In 

 such problems great results cannot be attained in a brief time but only through long continued 

 labours prefaced by appropriate preliminary studies." 



The great gorges traced out toward the middle of the Atlantic Ocean from the mouth 

 of the Congo on the east, and from the mouths of the Hudson, Delaware, Susquehanna and 

 Potomac rivers on the west, as well as the changes in the great lakes of America and Asia, 

 and also the palaeontological evidence of oceanic and continental deposits that have been 

 accumulating ever since the Permian era of the geologists, all agree with many other phenom- 

 ena in showing that great climatic changes have been in progress in our atmosphere since the 

 earliest ages, and it would not be strange if slighter changes should have continued to develop 

 during the past 4,000 years of the world's history, quite independent of solar changes. 



Glaciers. Among climatological studies the formation of glaciers has received continued 

 attention. W. Sievers at Carlsruhe, September 1911, discussed the glaciation in South 

 America: he attributes the secular variations to changes in temperature during the glacial 

 period produced by changes in solar radiation, but apparently he does not take full account 

 of the effect of the great changes on the earth's surface in altitude and moisture, and the 

 atmospheric changes due to volcanoes. 



Dr. P. Paschinger after a careful study of the relations between the snow limit and the 

 climate finds that these vary in different regions even during the same period of time; the 

 variations of the snow limit are greater on isolated mountains than in mountainous regions 

 and they are least between the tropics and on plateaus. The snow limit had its maximum 

 in the northern hemisphere after 1890 and its minimum about 1870. 



In an elaborate study of the light and air of Tiigh mountain regions, Dr. C. Dorno has 

 laid the basis for a physical study of the mountain climates of Switzerland, as minute and 

 precise as has been hitherto devoted to lower altitudes. He has given special attention to 

 the intensity and character of solar insolation, diffuse skylight radiation, terrestrial radiation 

 and atmospheric electricity. Among the interesting results attained by Dr. Dorno are the 

 determination of the great annual and diurnal variations of sunlight. 



Sunspot Influences. The last work from the pen of Prof. Simon Newcomb before his 

 death in 1909 discussed the meteorological evidences as to variations of radiation of heat from 



