746 COSMICAL PHYSICS 



indication of a warm current at a height of about seven miles, while 

 the stratification of the atmosphere as regards temperature, moisture, 

 and wind has been shown by the kite-flights at Blue Hill to be a 

 normal condition, and not merely confined to the high atmosphere, 

 as was formerly supposed. Daily soundings of the atmosphere to 

 the height of a mile or two are now being made with kites or cap- 

 tive balloons at the meteorological institutes of Berlin, Hamburg, 

 and St. Petersburg, and are furnishing valuable data concerning 

 the changes in the meteorological elements which occur simulta- 

 neously or successively in the overlying strata. 1 



Of the various unsolved questions relating to this subject, perhaps 

 the most important is whether the core of the cyclone possesses 

 the excess of temperature over the surrounding body of air which the 

 convectional theory of its origin requires. We need to know also 

 the height to which the cyclone extends, the circulation around it 

 at various levels, and further to generalize the theory of an accom- 

 panying cold-centre cyclone in the upper air, deduced by Mr. Clayton 

 from the Blue Hill observations. 2 Other important questions which 

 can be elucidated by future researches are the conditions favorable 

 for precipitation and the action of dust-nuclei in producing it, the 

 source of our American cold-waves, the exact relations of thunder- 

 storms and tornadoes to centres of pressure and temperature, and, 

 finally, the causes which, in the upper air, influence the trajectories 

 and velocities of the cyclones and anti-cyclones that give us our 

 broader weather features. When these correlations are determined 

 from the investigations of the free air now in progress, and we 

 possess a sufficient number of aerial stations to make it possible 

 to chart a daily map of the upper air, then we may expect an im- 

 provement in the weather forecasts. The prediction of fog over the 

 ocean on and adjacent to our coasts is of great practical importance 

 to shipping, especially off the banks of Newfoundland, and the 

 writer believes that meteorological kites flown from a steamer in 

 these regions would reveal the unknown conditions of temperature, 

 humidity, and wind in and above the fog-bank which might lead to 

 the prediction of the situations favorable to its formation. 



We now pass to another branch of meteorological research, namely, 

 the cosmical relations. It is incontestable that the sun, the source 

 of all terrestrial energy, has great influence upon the magnetic con- 

 ditions of the earth, but a consideration of the relation of terrestrial 

 magnetism and meteorology will be left to my colleague, Dr. Bauer. 

 The cause of atmospheric electricity has always been an enigma 

 to meteorologists, but the discovery of "ions," or "electrons," as 



1 Report of International Meteorological Committee, Southport, 1903. Appen- 

 dix n. 



2 Blue Hill Meteorological Observatory, Bulletin no. i, 1900. 



