276 T. .S. Hart: 



from tlie cast. That the north-west vaUoys have imt ceased is also 

 shown in the course of the north-east head of Main Creek and of the 

 Koonung Creek. 



North of the Springvale Valley the southerly fall is conspicuous, 

 but a north-westerly ridge again ap])ears through Wheeler's Hill. 



The Notting Hill Ghelfenhnm Axis. — The importance of this 

 divide is shown in the description. It is not a narrow ridge, but 

 a broad elevation or flat arch in shape, with a gradually decreasing 

 elevation to the south-west. Hence the actual heads of valleys are 

 not, and need not ever have been, on a straight line. 'J'he heads 

 are sometimes nearer to one side and sometimes to tlie other. The 

 general form of the axis is well shown l)y the 200, 150 and 100 ft. 

 contours. They run in a southerly direction on the west side, cross 

 tiie axis and lun away to the noi-tli-east. The fall in levels on the 

 crown of tlie axis is not, however, uniform. At Mitcham the 

 elevation is about 500; at Xotting Hill 320. Thence the fall is 

 somewhat rapid to the Ceiiti'e-road, where the 200 ft. level is 

 passed, but at Cheltenham the highest point is still 170. This is 

 ci'i-tainly an isolated summit, but the jjart of the axis ncu'th of 

 Cheltenham has jirobably suffered more severely, as the valleys are 

 near together, and in .some places nearly or quite cross the axis. 



The open valley at the head of Elsternwick Creek suggests that 

 ]»i"iha])S this divide was not original, but that valleys once headed 

 clear of it and ran across its position. But though the eastern fall 

 may have been steepened a little, there is no indication of any 

 general alteration of direction of How even in those valleys which 

 nearly cross the high land. The head of the Elsternwick Creek 

 alone might have been thought to have once started further east, 

 ajid to have lost its u])per i)art by a subsidence in this direction. 

 Imt thf valley of Keedy Swamp lias certainly always been an 

 easterly valley, and generally the whole series of valleys gives no 

 support to any other view than that this axis is original. The Hut 

 at the head of I'llsternwick Creek is no (hnibt due to the gieat 

 jtower of widening that a valh'v in these permeable beds act|uires 

 as soon as it reaehes an impeiiueable bottom. The permanent 

 water in brick holes east of Moorabbin station indicates that here 

 at least the i)ermanent water level is practically at the surface 

 (Ilo ft. above sea level), and the mere existeni-c of the briik j>its 

 shows that the bed of the valley is not in (he purer and moi^- 

 permeable sands. 



\ 1'lie iiortliwai'd pai't of tlie axis beyond Xotting Hill is indeed 

 broken liy the outlet from (ilen Waverley, but this is obviously 

 new, not an original feature. 



