CXxX. A. B. PORTUS. 
a minimum depth of water, say 10’, to permit of their passing 
over with the pumps at work at their load draft. In Engineering 
of December last, a vessel of this kind embodying all the latest 
improvements is described and illustrated. 
Recently the New South Wales sand pump “Neptune” dredged 
a channel a mile in length through the Clyde bar, its compara- 
tively sheltered position rendering the work practicable. Similar 
dredging, with such a vessel, could not be carried on at exposed 
bars, such as those at the entrances to the Tweed, Bellinger, 
Nambucca, Macleay, and the Manning, nor has there yet been 
built an American bar sand pump capable of deepening such river 
mouths, because there is not sufficient water on them to permit 
a ten feet draft vessel loading itself while crossing to sea. 
The author intended to refer to the large suction dredges work- 
ing at the mouth of the Mersey, and to describe the huge machine 
just started on the Mississippi, but as this paper has become 
tediously extended, he must ask those interested in dredging to 
read descriptions of the former in the ELngineer of October 6th, 
1893, and of the latter in the American Enginzering News of 
April 2rd, 1896, and in the Engineer of 3rd July, 1896. 
Recently the Minister for Public Works, on the recommenda- 
tion of Mr. Darley, m. Inst. c.8., Engineer-in-Chief for Public Works 
for New South Wales, has approved of an amount being placed 
on the estimates for the construction of a very light draft twin 
screw sand pump, arranged to pump sand into its hopper while 
slowly steaming over the shallow bars of the rivers of the es 
South Wales seaboard. 
