510 



SCIENCE. 



[N. S. Vol. II. No. 43. 



pressed force desired mil emerge by the 

 mutual destruction of other terms. Hence 

 the work is laborious and the residuals 

 small at the end of the first trip through 

 the observations. 



To obtain any result whatever it has been 

 necessary to adhere closely to certain pre- 

 cejits, and also it has been requisite to learn 

 to look beneath the apparent discordances of 

 curves which purported, but on the surface 

 seemed not, to be a record of the same fun- 

 damental pulsation. It was very natural 

 that those who seek to verify the results of 

 an investigator should expect to do so with 

 a brief treatment of the material involved, 

 and it could be easily shown that certain 

 criticisms which have been published were 

 based upon this process. Some highly 

 discordant curves are shown as arguments 

 against the truth of my conclusions, but in 

 every case so far as known some of the 

 precepts were violated and only a little 

 material was used. Negative results to be 

 valid against positive must be at least as 

 exhaustive, both as to the concepts em- 

 ployed and the amount of material in evi- 

 dence. In publishing conclusions it has 

 been my practice to retain partially tested 

 work till such advance had taken place as 

 to become a prett}' sure criticism of the re- 

 sults communicated, and it has therefore 

 been regarded as conducive to the progress 

 of the research not to complicate it with 

 discussions of the negative arguments, 

 which were obviously violating certain 

 precise rules of procedure as yet unex- 

 plained to the public. 



The ultimate goal of interest to the 

 Weather Bureau is the improvement of the 

 forecasts, whether in reading the daily 

 maps or in f>redicting seasonal conditions 

 for a year or more. Meteorologj^ had con- 

 tented itself with combinations of three 

 forces, the earth's gravitation, the earth's 

 rotation and equatorial insolation, acting 

 upon the fluid atmosphere, in order to ex- 



plain the observed effects in the motions of 

 the air. The result has not satisfied stu- 

 dents of the subject. The first point to 

 determine was whether the sun did or did 

 not transmit other energy to the earth, and, 

 if it did, what kind of energy. The proba- 

 bility was that the auroras, the magnetic 

 storms and earth currents, certain spas- 

 modic actions in the electricity and mag- 

 netism of the earth's field and motions of 

 the atmosphere, the sun spots and the 

 coronal output, all belonged to one funda- 

 mental system, though no intelligible notion 

 had been proposed that could explain the 

 interrelation philosophicallj\ The great 

 distance of the earth from the sun seemed 

 a barrier to one obvious explanation, so that 

 the work was never seriously undertaken 

 to test the validity of it. 



My own attempts to solve the question 

 of the meaning of the stream lines seen in 

 the corona during an eclipse of the sun 

 suggested and strengthened the working 

 hypothesis that the whole unexplained 

 system might be referred to the sun as a 

 magnet in dynamic oj)eration, and that live 

 lines of magnetic force originating in the 

 sun were propagated to the earth in wide 

 sweeping curves, where the energj^ was ex- 

 pended in vai-ious operations, such as those 

 just mentioned. Progress was also made 

 in computing and mapping out the system 

 of forces causing the diurnal and annual 

 swings of the magnetic needles, which 

 showed plainly that a complex field of 

 mechanical forces besides gravitation sur- 

 rounded the earth at its surface. Such 

 forces must necessarily be referred to the 

 electro-magnetic radiation of the sun, be- 

 cause the system was instantaneous and 

 observations covering half a century could 

 be combined without reduction for secular 

 variation; and also because the entire sys- 

 tem wanders up and down the earth M'ith 

 the change of the position of the axis of the 

 field, as the sun moves in declination. 



