PROCEEDINGS OF SECTIOX E. 523^ 



Before our return to camp a substantial " pile " was placed on 

 the summit of the peak, which can now be seen clearly from the original 

 trig, station, (2) about eight miles south of it. 



SYNOPSIS OF PAPER. 



The orography of the north-eastern mountain system of Tasmania 

 is first dealt with. 



Ben Lomond, the finest and loftiest isolated range in Tasmania, 

 is shown to form the trunk of a system from which spring two wide- 

 stretching areas in the form of a lengthened plateau, averaging 2,0()0ft. 

 in altitude, and which reach out to the north-west and north-east 

 respectively. From these areas rise lofty tor-like mountains ; those 

 on the western part of the plateau being Mount Ben Nevis, Mount 

 Barrow, and Mount Arthur ; those on the eastern arm. Mount Saddle- 

 back, Mounts Victoria and Albert, Mount Maurice, and the " Blue 

 Tier." The mountain chain so formed is shown to be separated in a 

 very distinct manner from those of the northern half of the colony by the 

 River South Esk, which rises to the north-east of the plateau, and after 

 almost completelv encircling it in its course, falls into the sea in con- 

 fluence with the Nor.th Esk as the picturesque estuary called the Tamar.. 



The climatic conditions in this part of the State are shown to be 

 much affected by the lofty chain of mountains enumerated, heavy 

 precipitation occurring to the north and north-west of the range, when 

 the south-east and eastern low country, sheltered by the proximity of 

 Ben Lomond during westerly weather, experiences but little fall. The 

 contrarv conditions obtain during heavy easterly weather on the- 

 Tasmanian littoral, bounded by Tasman's Sea. 



The Ben Lomond plateau is completely surrounded by a precipi- 

 tous, and in some places lofty, diabase escarpment, which rises from 

 the surrounding subsidiary tiers and supports it at elevations above 

 sea-level of from 4,500ft. to above 5,000ft. The lofty upland so 

 contained has the shape of an irregular rhomboid, with a bearing 

 from south-east to north-west. 



Its surface is composed topographically of two main divisions, 

 divided by a deep depression crossing it from east to west, and into 

 which " trough valleys," or hollows, with a maximum depth of about 

 230ft. enter from the northern half ; while in the southern portion similar 

 depressions, rising in its northern and eastern tracts, converge towards 

 a deeper valley, containing the sources of the Nile River, and issuing 

 finally by a profound gorge through the western escarpment. 



The sides of these valleys are formed of rugged slopes of diabase 

 talus, alternating with castellated portions formed of the columns 

 in situ. The intervening moor-belts are, some of them, rugged, with 

 basaltic tors and peaks, while others present a more even surface, 

 with occasional tracts bare of alpine vegetation, and showing the 

 smooth, geometrical structure of the cooled irruptive rock. 



(2) This was named " Legge's Peak " by Mr. L. Giblin last year on his first 

 ascending it ; the whole group of prominent heights, of which it forms the cul- 

 minating point, having been named by the writer the " Giblin Fells," after that 

 gentleman and his father, the eminent Judge and Chief Justice. 



