Chalk and Flint Formation. 43 



a minute degree a slower rate of rotation ; just as a 

 longer pendulum swings more slowly than a shorter. 

 And as an accretion of materials from meteoric 

 sources is still slowly going on, a very minute 

 decrease of the velocity of rotation may be expected 

 to continue. Accordingly it is remarkable that 

 astronomers of late, since Professor Adams's cor- 

 rection, in 1853, of the calculations connected with 

 the secular acceleration of the moon, have come to 

 the conclusion that the earth's rotation has been, 

 and is, getting slower in a very minute degree ; 3 

 which they have been exercising their ingenuity to 

 account for, but which may have in these facts a 

 sufficiently patent explanation. Is not, then, that 

 ancient traditional, perhaps even patriarchal doctrine, 

 which Leucippus had got hold of along with other 

 parts of the philosophy brought by Pythagoras from 

 the East, well worthy to be regarded as the more 

 consonant with reasonable probability and with 

 known facts, though extensively modified by other 

 causes known to be, and to have long been, in 

 operation ? 



I must be content to leave these questions. It is 

 of more immediate importance to observe that the 

 subject may be shown to have a bearing on the 

 question between the ancient record of the universal 

 deluge, and the alternative modern hypothesis of a 

 deluge of solid ice instead of water, with glacial 

 ages upon ages of ice from three thousand to eight 



8 See, among other authorities, M. C. E. Delaunay, " Sur le 

 Relentissement du Monvement de Rotation de la Terre." 8vo. 

 Paris, 1866. The subject is popularly referred to by the late E. 

 B. Denison, in his "Astronomy without Mathematics," 3rd Edit., 

 1867 (Christian Knowledge Society). Mr. Denison states that 

 M. Delaunay's conclusions are accepted even by the late Astronomer- 

 Royal, Sir George B. Airy. 



