APPENDIX. 



283 



movement ? If so, many difficulties would vanish ; among them those 

 which were first mentioned, and those perplexing anomalies on the 

 south coast of New Holland." — (Jour. R. Geog. Soc. vol. vi. part II. 

 p. 336.) 



It might have heen concluded that these questions had scarcely- 

 been noticed, as I heard nothing on the subject, had I not lately read 

 the following remarks in a work published in 1837. Whether their 

 author ever saw the questions, I do not know ; but as his observations 

 bear strongly upon the subject, and are those of an eminent mathe- 

 matician, I quote them verbatim :~ 



" Suppose several high, narrow strips of land were now to encircle 

 the globe, passing through the opposite poles, and dividing the 

 earth's surface into several great, unequal oceans ; a separate tide 

 would be raised in each. When the tidal wave had reached the far- 

 thest shore of one of them, conceive the causes that produced it to 

 cease ; then the wave thus raised would recede to the opposite 

 shore, and continue to oscillate until destroyed by the friction of its 

 bed. But if instead of ceasing to act, the causes which produced 

 the tide were to re-appear at the opposite shore of the ocean, at the 

 very moment when the reflected tide had returned to the place of its 

 origin, then the second tide would act in augmentation of the first ; 

 and if this continued, tides of great height might be produced for 

 ages. The result might be, that the narrow ridge dividing the adja- 

 cent oceans would be broken through, and the tidal wave traverse a 

 broader tract than in the former ocean. Let us imagine the new 

 ocean to be just so much broader than the old, that the reflected tide 

 would return to the origin of the tidal movement half a tide later 

 than before ; then instead of those two super-imposed tides, we should 

 have a tide arising from the subtraction of one from the other. The 

 alterations of the height of the tides on shores so circumstanced might 

 be very small, and this might again continue for ages, thus causing 

 beaches to be raised at very different elevations, without any real 

 alteration in the level, either of the sea or land." — (Babbage's Ninth 

 Bridgewater Treatise, pp. 248, 249.) 



Additional data, and leisure to reflect upon them, have tended to 

 confirm the view taken previously to asking those questions in the 

 Geographical Journal ; but before stating this view more explicitly, 

 it is necessary to lay facts before my readers, from which they may 

 judge for themselves. 



b b 2 



