January 1, 1904.] 



SCIENCE. 



33 



the same curve as the solar circulation, is 

 directed upon the earth in polar curves as if 

 coming from a distant spherical magnet, and 

 not along the radial lines of electromagnetic 

 radiation. It is not easy to account for these 

 disturbances by flights of ions from the sun 

 along the lines of the electromagnetic me- 

 chanical pressures. The further the discus- 

 sion of the cosmical observations is pressed, 

 the more positive becomes the evidence that 

 the sun sustains a strong magnetic field, which 

 responds to a variable magnetization vrithin its 

 nucleus. Radiation from the solar surface has 

 another source of energy, namely, the atomic 

 and molecular vibrations of the constituents 

 of the outer envelope, as the photosphere, 

 and hence much may go on at the surface 

 which is not immediately representative of 

 the state of the nucleus. Thus, the outpour- 

 ing of heat, light and the ions streaming 

 along the radii of electromagnetic pressure, 

 together with the curved rays seen in the 

 corona, consisting of positive and negative 

 charges of electricity moving about a mag- 

 netic field, may take place at a given time 

 in one way, while the nucleus is operating 

 temporarily in another manner. Thus there 

 may be divergences instead of synchronisms 

 between the individual outbursts of spots and 

 prominences on the solar surface as compared 

 with the terrestrial magnetic storms and 

 auroral displays which proceed from the nu- 

 cleus, without in the least invalidating the 

 claim that in general substantial synchronism 

 exists. When sufficiently long intervals are 

 taketi, as a year, or possibly a few months, 

 the conditions of the earth's atmosphere are 

 affected by and vary with the changes in the 

 solar processes. There has been much con- 

 fusion in scientific writings arising from the 

 failure to distinguish between physical actions 

 at the surface and the interior of the sun, and 

 many unsound criticisms have been published 

 in consequence of it. The problem is com- 

 plex, but with the growth of reliable data it 

 is becoming yearly more promising of a satis- 

 factory solution, and it is always interesting. 

 The Circulation of the Earth's Atmosphere. 

 (Fig. 3.) — The meteorological theories of the 

 motions of the atroosphere of the earth are 



now in a transition state; the old are passing 

 away, and new ones are being constructed. 

 Ferrel's theories of the structure of cyclones 

 and anticyclones, as well as of the general 

 cyclone of the hemisphere, have crumbled 

 under the strain of modern observations. The 

 ' Cloud Report ' of the Weather Bureau, 1898, 

 discarded both the Ferrel and the Oberbeck 

 local and general vortices, and indicated a 

 new path of research. The International 

 Meteorological Committee has at last reached 

 the same conclusion. (See 'Reports' for 

 1902 and 1903.) The problem at present is 

 one of rebuilding in conformity with the facts. 

 The general equations of motions were very 

 briefly discussed by H. von Helmholtz, who 

 introduced into them potential temperatures, 

 in place of the density, and the corresponding 

 constant angular momenta. From these equa- 

 tions arise three distinct cases, one of which 

 was considered somewhat fully by him. The 

 second case has been applied by Emden to 

 solar circulation as above indicated, and the 

 third case has not yet been sufficiently recog- 

 nized by any one. Case I. shows that there 

 are discontinuous surfaces of separation be- 

 tween layers having different temperatures 

 and velocities, and that in the earth's atmos- 

 phere these should extend from about lati- 

 tude 35° towards the poles, rising higher above 

 the surface with progress poleward. Case 

 III. gives surfaces sloping towards the earth 

 from the equator up to about latitude 35°. 

 This system differs entirely from Ferrel's, 

 which adopted the canal theory of circulation 

 with poleward currents at high elevations. 

 These do not in fact exist, but there is evi- 

 dence that the surfaces here specifled are in 

 conformity with the observed circulations as 

 modified by mixtures. The local cyclones of 

 the temperate zones are built up of counter 

 currents of different temperatures derived 

 from these general conditions, which in low 

 levels near the surface of the ground under- 

 flow the eastward drift of the upper strata. 

 The configuration of the isobars of the local 

 cyclones observed on the sea level extends 

 upward two or three miles with diminishing 

 intensity, i till absorbed in the system of nor- 

 mal isobars pertaining to the season of the 



