ADVISORY COMMITTEE ON METEOROLOGY 8 1 



(b) General meteorology of the upper atmosphere, to be studied 

 by means of clouds, balloons, kites, mountain stations, polarization 

 of skylight, or any other method of observing the upper air. 



(c) General meteorology of those parts of the ocean not already 

 provided for. 



(d) Daily weather maps of the world in general, compiled by in- 

 ternational co-operation, from reports received by mail from obser- 

 vations on land and at sea. 



(e) The relations of meteorology to terrestrial magnetism, at- 

 mospheric electricity and solar radiation, including the absorption 

 of sunshine by the air. 



5. Among the minor subjects that may be taken up by single 

 individuals in the physical laboratory or meteorological observatory 

 are the following : 



(f ) All problems relating to thermometry, barometry, actinome- 

 try, anemometry, hygrometry, pluviometry, nephelometry and 

 other branches of instrumental work. In every field of observa- 

 tion we need continuous self-registering apparatus more sensitive, 

 more delicate and more reliable than we at present have. 



(g) Experimental laboratory methods should be devised to eluci- 

 date the physical processes of the formation of cloud, fog, rain, 

 dew, frost, snow and hail, which work will necessarily be a continu- 

 ation of that already done by Carl Barus andC. T. R. Wilson, so far 

 as concerns clouds and rain, and that done by Mr. W. A. Bentley, 

 of Jericho, Vermont, as far as concerns the microphotographs of 

 snow crystals. 



6. But, as above said, all these observational researches must be 

 supplemented bj^ mathematical work on the dynamics of the earth's 

 atmosphere. Only a few elementary problems under this category 

 have as yet been solved satisfactorily, and perhaps those that remain 

 cannot be solved until new branches of mathematical ansJysis shall 

 have been developed for this purpose. It is in this line of work that 

 we most earnestly anticipate the assistance of the Carnegie Institu- 

 tion . A few years ago meteorologists were encouraged to find that von 

 Helmholtz had turned his attention in our direction . But his death 

 in the prime of life crushed our hopes. At the present time there 

 are several prominent workers on the mechanics of the atmosphere, 

 such as Bigelow in America, Bjerknes and Ekholm in Sweden,. 

 Moeller, Sprung, Wien, Pockels and von Bezold in Germany, 

 Marchi in Italy, Pernter and Margules in Austria, Diro Kitao in 

 Japan, and Brillouin in Paris. These all combine a good practical 



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