December 2, 1910] 



SCIENCE 



119 



belt, and an increasing eastward drift 

 from the surface upwards in the temperate 

 zones to about 13,000 meters, where it be- 

 gins to fall off at the isothermal level. 



The Consequences of this Distribution of 

 Temperatures in the Atmosphere. — (1) 

 Any increase in pressure in one locality is 

 compensated by a corresponding decrease 

 in another locality, in order that the total 

 pressure of the atmosphere may remain a 

 constant. I have shown that an increase 

 in solar radiation is attended in general by 

 an increase of pressure in the hemisphere 

 whose focus is the Indian Ocean, but a 

 decrease of pressure in the American con- 

 tinent. (2) An increase of solar radiation 

 means an increase of temperature through- 

 out the tropics, and an increase in the west- 

 ward drift, but a decrease of temperature 

 in the temperate zones with an increase in 

 the eastward drift. This strengthening of 

 the two branches of the hemispherical 

 torque, with opposite temperatures at the 

 surface from the increase in the energy of 

 the solar radiation is essential in order to 

 preserve the constant rotation of the earth 

 on its axis, which is observed by astronom- 

 ical methods to be the fact. This necessary 

 inversion of pressure and temperature in 

 the several parts of the earth's atmosphere, 

 due to the same external change in heat 

 energy from the sun, not only reconciles a 

 number of conflicting researches on isolated 

 phenomena, but it tends to classify a vast 

 number of interrelated but apparently ir- 

 reconcilable facts referred to the old canal 

 theory. 



The Local Circulations in the Atmos- 

 phere. — The early theoretical studies on 

 cyclones and anti-cyclones proceeded on the 

 unnecessary supposition that these circula- 

 tions are warm-centered or cold-centered 

 about the axis of gyration. The argu- 

 ments for this theory were based iipon the 

 easy solutions of the equations of motion, 



wherein Farrel assumed one and the Euro- 

 pean meteorologists another possible solu- 

 tion. The obsei^ed facts by means of kites 

 and balloons do not justify such distribu- 

 tions of temperature about an axis, but 

 rather such temperatures as would place 

 the centers of gyration near the borders of 

 the warm and cold interflowing currents 

 just described. The hydrodynamic and the 

 thermodynamic relations in this case be- 

 come excessively complicated in the case 

 of cyclones, which are really very irregular 

 circulating structures, though hurricanes 

 and tornadoes conform closely to simple 

 vortices. 



Solar Radiation and Terrestrial Fields 

 of Heat, magnetic and Electric Energy. — 

 I became convinced, from a study of Max- 

 well's "Electricity and Magnetism," in 

 1889, that the most probable explanation 

 of the outstanding problems in terrestrial 

 magnetism and electricity would be found 

 in the transformations of the electromag- 

 netic energy of solar radiation in the 

 earth's atmosphere. At that time the only 

 known type of motion was to be found in 

 the kinetic theory of gases, and these two 

 systems were not very readily harmonized. 

 The discovery of ionization, and the fact of 

 electrons in motion in the air, accounting 

 for induced magnetic fields and conduc- 

 tivity due to moving electric charges, put 

 the entire subject on a new basis of 

 thought. This atmospheric ionization was 

 caused either by the transformation of the 

 very short wave rays from the sun, or pos- 

 sibly by cathode corpuscles in bombard- 

 ment from the sun to the planet, in the 

 high levels where low densities prevail in 

 the gases; or, else, by friction electricity 

 generated among the molecules, dust, va- 

 por, water and ice particles in the lower 

 atmosphere near the surface in the lotv 

 levels; or, finally, by radioactive radiations 

 and emanations from the body of the earth 



