420 A. Winchell — Trend and Crustal Surplusage. 



of the earth's wrinkles was first conceived hy me in the early 

 spring of 1885.* To say that the equatorial protuberance un- 

 derwent a secular subsidence is to say that the equatorial cir- 

 cumference of the earth, as an effect of retarded rotation, has 

 shortened more than the polar — that indeed the polar circum- 

 ference has lengthened. That is, the greatest lateral pressure 

 has been experienced from east and west around the equator. 

 An excess of pressure in this direction must develope crustal 

 changes having north and south continuity. Whether the 

 results were foldings or crushings together, or over slippings, 

 their axis-trends would be meridional. This cause then, con- 

 spired with early tidal action in predetermining the direction 

 of the longitudinal dimension of the earth's structural features. 



3. The same cause produced crustal surplusage around the 

 equatorial zone. Aside from refrigerative contraction of the 

 earth, the equatorial circumference diminished while the polar 

 increased. This cause alone would, therefore, have developed 

 meridional mountain plications over the protuberant belt. If 

 the crustal surplusage resulting from refrigerative contraction 

 was less than existing mountain plications demand, here is a 

 cause which would supplement the supply from that source. 

 Careful measurements may show that the supplementary sur- 

 plusage needed is not greater than calculations may prove this 

 cause capable of affording. If so, the contractional theory will 

 experience the relief which every physical geologist must have 

 desired, if not anticipated. 



4. Tne meridional predisposition depending on subsidence 

 of equatorial protuberance would be developed north and south 

 of the equator as far as the parallels marking the limits of the 

 protuberance. The meridional predisposition induced by lunar 

 tidal action would be experienced north and south of the 

 equator to the latitude marking the limits of the prolate tidal 

 swell resulting from the moon when over the equator, plus the 

 amount of the moon's lunar-monthly declinations. The extent 

 of these actions, therefore, is as great as the actual trends de- 

 mand ; and embraces also, all the strongly plicated portions of 

 the earth's surface. 



einmal die Ursache deutlich dar, die den Mond genothigt hat, in seinem Umlaufe 

 um die Erde imtner diesselbe Seite zuzukehren." He proceeds to say that this 

 phenomenon is not due to overloading on the nearer side; that the influence 

 began at the moment when the moon abandoned the earth ; that the moon was 

 at first in a fluid state, and that it then rotated with much greater velocity than 

 at present. This historic fact deprives Mr. Ferrel of priority, but does not 

 diminish the credit due him. Kant's memoir was dated at Konigsberg, the iden- 

 tical spot where Helmholtz. one hundred years later, put forth the same thoughts 

 as original with him. 



* It is but just credit to a sagacious pupil, Mr. W. E. Bond, of Albion, N. T., 

 to say that he embodied a clear and original exposition of the principle in a thesis 

 presented in June. 



