46 ANNALS NEW YORK ACADEMY OF SCIENCES 



order, therefore, to have a better idea of the variations in tlie far western 

 states, I had to take fourteen more stations whose records begin a few 

 years later than 1873. I made, for these sixty-four stations, consecutive 

 totals of ten-yearly means and the departures of these totals from the 

 general or normal means of Bigelow's tables, and then I inscribed the 

 figures so obtained on maps and drew the lines of equidepartures. 



When one takes into consideration the facf that some of the departures 

 are obviously wrong, the series of observations not being homogeneous, 

 and when one looks on the maps and sees how far apart some of the sta- 

 tions are and how problematical these departures are, one arrives at the 

 conclusion that all that may be said about long-range variations of tem- 

 perature is to a great extent purely hypothetical. 



It is undeniable that long-range variations exist, but a search for the 

 periods of these variations is at present hardly justifiable, as an inspection 

 of my maps demonstrates at once. The oscillations of temperature are 

 indeed the product of a dynamical plienomenon, and it is of course only 

 in the case of stationary oscillations that the phenomenon would be sim- 

 ple enough to allow the application of statistical methods to its study. 

 Since, however, the phenomenon is dynamical, all (apparent) knowledge 

 gained by a purely statistical treatment of the subject is defective and 

 may be discarded, or must at least be considered as being an insufficient 

 proof. 



Let us examine the maps. 



The departures for the decade of 1873-1883 give a map showing the 

 existence of a macropleion covering practically all the area of the United 

 States and extending most probably far north into Canada and south 

 over the West Indies. Negative departures^" are to be observed along 

 the Atlantic coast, in Boston, New York, Philadelphia and Wihnington, 

 and also in San Diego, Calif. The positive departures are highest in 

 Duluth, La Crosse, Chicago, Indianapolis, Cincinnati, Nashville and, 

 farther south, in Key West, where the departure is -{- 0.9 F. The highest 

 figures are -f- 1.3 in La Crosse and Cincinnati. The macropleion has a 

 well marked crest extending NNW.-SSE. 



During the following couvsecutive decades, this crest persists with a 

 striking tendency to assume a N.-S. direction and, at the same time, we 

 notice a slow displacement of the macropleion toward the south and the 

 more or less gradual development of a macromeion in tlie west. 



A radical change in this nearly stationary situation occurs between the 

 decades 1877-1886 and 1878-1887. I reproduce the following four maps 



" The figures — 0.3 for Pittsburgh and KnoxvlUe are considered as being evidently 

 wrong. 



