386 THE POPULAR SCIENCE MONTHLY. 



a somewhat regular gradation, two to five degrees, during one, two, or 

 three years. And in the approach to maxima a rise nearly as precipi- 

 tate. This has its parallel in the rainfall — the precipitation experi- 

 encing a sudden increase in the high extremes of from eight to thirteen 

 inches, and during low extremes of from four to eight inches, within 

 one or two years. 



In these records of the past century, imperfect as they are, will be 

 found suggestions of more subtile and fundamental laws. The reader 

 may notice a succession of three large sun-spot waves or periods fol- 

 lowed by three lesser ones. They call to mind that succession of 

 waves in the sea, called by sailors "the three sisters," and of the three- 

 day weather period with w^hich we are familiar. The conjecture may 

 be warranted that we have here an indication of a major vibration of a 

 six-period duration. It may be that all these cycles are but members 

 of a grander whole, whose circles reach beyond our present ken, and 

 to a perfect conception of which we may never attain, except per- 

 chance in that good time coming, when man's knowledge shall equal 

 his aspirations. These considerations, and many more of which we 

 are in ignorance, must enter into a calculation of the true horoscope 

 of the future. 



Nevertheless, we know that Nature governs by unvarying law. 

 Assuming that her periodicities will bring about the same average re- 

 sults in the future as in the past half-century, I might undertake to 

 be in some sort her interpreter of the coming events which cast their 

 shadows before, along the pathway of a few unborn years ; provided the 

 same latitude be accorded me which was claimed by the old almanac- 

 makers, to qualify the record with " about . . . these . . . days." 



In each of our half-century cycles we have seen that there are five 

 maxima and five minima of sun-spots, whose periodic times average 

 for the first cycle a little more than eleven and a half years, and for 

 the last cycle a little less. We may reasonably conclude that the next 

 half-century will witness no material change, but that the like phe- 

 nomena will continue, with a mean period of about eleven years ; 

 also, that the temperature and the rainfall will continue to exhibit 

 their dependent phenomena as before. On this basis let us construct 

 our diagram for the coming years. 



Premising that the sun-spot curve, which for five years bad been 

 on the rising scale, attained its maximum in 1882, we may infer that 

 the temperature is now on its descending grade, and should reach its 

 minimum by 1889 or 1890. The yearly mean, which for ten years 

 past has maintained an unusually high degree, with small range, will 

 fall rapidly five degrees or more. " Look out for . . . cold . . . weather 

 . . . about . . . these . . . years." The wary will also provide for cold 

 winters about the years 1901, 1912, and 1923, and for epochs of high 

 temperature about 1894, 1905, and 1917. 



The rainfall, which, in accordance with its law of opposition and 



