320 WIDE CLEAR SPACE. 



five miles, when it is forty fathoms and upwards, 

 and then suddenly to two hundred fathoms, with 

 which sometimes no bottom could be reached within 

 a quarter of a mile of the edge of the bank. The 

 soundings on the bank were mostly sand, with frag- 

 ments of shells and corals ; but instead of being 

 wholly siliceous, as near Breaksea Spit, it was 

 found, near the Capricorn Group, that the smallest 

 grains were calcareous, everything brought up from 

 the bottom being soluble in muriatic acid. 



North of the parallel of 23° 10', there is an open 

 space of sea, in which no reefs occur, about fifty miles 

 wide from north to south; and the bank of soundings, 

 instead of having a steep, well defined edge, slopes 

 out very gradually far to the eastward. The flat, 

 of about twenty fathoms, extends out as usual from 

 the main land for about thirty or forty miles, and then 

 gradually deepens, till seventy, eighty, ninety, and a 

 hundred fathoms are successively attained, twenty 

 or thirty miles eastward of the boundary of the line 

 of soundings, as it exists to the southward. The 

 character of the bottom likewise changes from a 

 coarse coral sand to the finest possible mud, of a 

 light olive green colour, in which the lead often 

 wholly buried itself on reaching the bottom. This, 

 when dried, was also entirely calcareous, and wholly 

 soluble in muriatic acid. 



In lat. 22° 25' and long. 152° 40' commences a 

 very strong body of reefs, the boundaries of which 

 run towards the north and north-west respectively, 



