F. H. Bigelow — Inversion of Temperatures, etc. 447 



that the four mean tracks, North Low and High, South Low 

 and High, occupy from year to year. The North High and 

 the South Low move in opposite directions to the North Low 

 and South High, the latter moving north with increasing 

 intensity of the magnetic system. The units are 3 miles in 

 latitude, and the range in the sun spot period is about 120 

 miles. " Movement in Longitude " indicates the variation on 

 the mean eastward drift of the meteorological conditions, taken 

 year by year, and the numbers are here given with the signs 

 inverted. This shows that the increase in eastward movement 

 is for the years of decrease in the magnetic intensity. The 

 physical interpretation of these inversions is at hand, but can- 

 not be explained in this abstract. The unit is 1/37 miles, and 

 the change in movement ranges about 50 miles per day; that 

 is in years when the magnetic intensity of the sun increases, 

 the normal tracks move northward, and the eastward circula- 

 tion slows down. 



" Temperature Amplitudes " relates to the changes in tem- 

 perature in the 26*68 day periods from year to year. By sum- 

 ming the residuals, already explained, without regard to signs, 

 the amplitudes are obtained, and the sum of these for each 

 year is entered in the table. They are only relative numbers 

 but show the annual changes. The " mean annual tempera- 

 tures" are derived from 80 Weather Bureau Stations, the 

 annual temperatures being tabulated, summed and the residuals 

 entered, these being the surviving residuals for each year. 

 They are however entered with the opposite signs, and express 

 the fact that the years of an increase of solar magnetic inten- 

 sity are those of colder temperature in the United States, the 

 explanation of the phenomenon being in harmony with the 

 theory of anticyclonic and cyclonic circulations which I have 

 briefly described in an earlier paper. (Astron. and Astro- 

 Phys., Jan., 1894). 



All of these sets of numbers may be treated as merely rela- 

 tive values of one fundamental impulse, namely the solar mag- 

 netic field, and hence can be reduced to the same amplitude, 

 the mean of the last relative numbers being a closer representa- 

 tion of the average system than either of these sets alone. It 

 should be noted that on plotting in a diagram, the four sets 

 clearly agree among each other in producing the same curve, 

 even to minute details, the years 1883, 1884, near the crest 

 alone showing some uncertainty in the curves. 



" Magnetic Intensity " gives the annual variations of the 

 European magnetic field, as derived for five or more stations, 

 the data referring to the horizontal component, a = 0'000084 

 C. G. S., and the unit being the sixth decimal. The sun spot 

 numbers are taken from the Jahrbuch der Astronomie und 



