16 
SURVEY OF THE INTERTROPICAL 
1818 . 
January 
21 — 31 . 
pounds and a half, and was three feet and a half 
long. The mouths of all the creeks and inlets 
were planted with weirs, which the natives had 
constructed for the purpose of catching fish. Mr. 
Roe, on his excursion round the harbour, counte 
eleven of these weirs on the flats and shoals 
between the two rivers, one of which was a 
hundred yards long, and projected forty yards, 
in a crescent-shape, towards the sea; they were 
formed by stones placed so close to each other 
as to prevent the escape, as the tide ebbed, of 
such fish as had passed over at high water. This 
expedient is adopted in many parts of the conti- 
nent; it was observed by Lieutenant Oxley, R.N., 
the surveyor-general of New South Wales, in his 
journey on the banks of the Lachlan River . the 
same was also seen by me on several parts of 
the North-West Coast ; and, from its being used 
on the S.E., S.W., and N.W. Coasts, it may be 
concluded to be the practice throughout the 
country. 
While waiting for an opportunity of leaving 
this harbour, Mr. Roe assisted me in making a 
survey of the entrance, in the hope of finding 
it more available for large ships ; but in vain , 
for ships drawing more than twelve feet water 
cannot pass the bar. The rise and fall of the tide 
is not only very inconsiderable, but also very 
