758 
PROCEEDINGS OF SECTION 11. 
solid ground on shore. These, with longitudinal walings running 
parallel to the river, also bolted to the pileheads, and with diagonal 
braces, all form a timber framing behind the wall, which acts as a firm 
stay to it, and effectually prevents any tendency to slip forward into 
the river. 
The space behind the walls is filled up with earth, and covered in 
by a hardwood timber decking. On the front of the wall next the 
river strong fenders of cast iron are inserted, and tied into the concrete 
work and timber framework. These fenders extend from the top of the 
wall down to a few feet below low-water mark to receive the chafing 
of the shipping. 
The whole forms a quay wall which is absolutely secure from the 
attacks of the Teredo , as the only surfaces exposed to the water are of 
cast iron and cement, concrete. 
The concrete of which the walls are composed was laid partly 
under low-water level, and for this purpose special bags were designed 
by Mr. W. Burns, contractor, to allow of the concrete being emptied 
on the bottom of the river or on the concrete wall when the bag was 
resting on the bottom. This is a sine qua non with subaqueous 
monolithic concrete work, as distinguished from bag concrete work, on 
which the concrete is laid in position in the bag. In order to test the 
efficiency of the bags for depositing the concrete without separating 
the materials of which it was composed and washing out the cement, 
which is the result when concrete is allowed to fall even a few 
inches through water, J carried out a scries of experiments, in which I 
had the concrete tipped under water into wooden cases, which were 
afterwards drawn tip for the examination of the concrete, which was 
found to be sound and good. 
With, respect to the union of the concrete with the timber, I may 
state there is no difficulty on that point. Ail the piles were barked 
and the sap also removed, and it has been found on examination of 
work of this kind, after eighteen months have elapsed, that the concrete 
adheres most tenaciously to the timber. 
After a few years’ test of the work in this new wharf, the result 
is highly satisfactory ; in fact, it forms a permanent structure adapted 
to river or marine work at a cost not much exceeding that of a timber 
erection, which is liable to be destroyed in a few years. 
6.- SOME NOTES ON THE RIVER FITZROY, CENTRAL 
QUEENSLAND. 
By THOMAS PARKER , C.E, Town Surveyor and Engineer of Waterworks , 
Rockhampton, 
The river Fitzroy is one of the most important of the many 
rivers on the eastern side of Queensland which flow into the Pacific 
Ocean, and it drains a large portion of that colony. The large district 
forming the gathering-ground of its waters extends from the Great 
Dividing Range on the south to Mount Britten on the north, a distance 
of about 260 miles, and from the city of Rockhampton on the east to 
the Drummond Range on the west, a distance of about 190 miles. 
This river is formed by three principal tributaries — the Dawson River, 
