CENTRIFUGAL PUMP DREDGING IN N.S.W. CXV. 
ing, and renew them, keeping always in reserve a duplicate pump 
to avoid delay. Wear of the bearings is provided for by steel or 
gun metal bushes, and by a water jet keeping back any escaping 
sand, The discharge from the pump of the “Neptune” is so 
arranged that the material can be delivered over the side to port 
or starboard or into the hopper. Over the hopper and extending 
throughout its length are two 16” pipes, fitted with valves under- 
neath to control the exit of the sand and water, which, after 
leaving the pipes, falls into perforated troughs, the object being 
to separate the sand from the water. Coombings 30” high are 
fitted round the hopper, and the water with some sand flows over 
the top until the solid material rises to the required height. 
When hopper loading is being done two anchors only are used, 
one ahead and the other astern. When reclamation with silt 
from the “Neptune” and “Juno” was started, much difficulty 
Was experienced with the flexible joints sent from Holland with 
the pipes, and the author designed the accommodation gimbal 
joint, shewn on the attached sheet, which permits of greater 
range vertically and horizontally than even the ball and socket 
Joint, and being very strong has been found specially suited for 
use in rough water. (Plate 7.) 
The Dutch type of sand pump just described, although admir- 
ably adapted for sand, is entirely unsuited for clay dredging, and 
We are indebted to American ingenuity for machines fitted for 
dealing with all kinds of material, among them the “ Von Schmidt’ 
and the “ Atlas” dredges. Each machine has many admirable 
features, and both are capable of doing all that is claimed for 
them. The “Atlas” machine is described and illustrated by 
Mr. Derry, M.Ist.c.z., in a valuable report to the Victorian 
Government written in 1885, and improved dredges partly on 
the “Atlas” principle are fully described in the United States 
Public Works Guide and Register of 1895. The ‘* Von Schmidt ” 
machine will now be briefly referred to ; but persons interested in 
dredging work should inspect the New South Wales suction 
dredge “Groper,” as that machine embodies all the latest im- 
