CXXVIII. : DISCUSSION. 
at 13d. per ton, with screw hopper bucket dredges working in 
free material at about 24d., and with stationary bucket dredgers 
and steam hoppers the cost may be taken at 33d. With hired 
plant and for small quantities, the price will reach as much as 
1s. 6d. or even 2s. per ton.” On the Tyne, Mr. Wheeler says, 
“the cost per ton for bucket dredging was 3:39d. per ton includ- 
ing repairs but not interest on outlay or depreciation.” 
The cost of work with ordinary sand pumps and with bucket 
dredges excluding interest and depreciation is (notwithstanding 
the eight hours system and higher rates for labour here) practically 
the same in Europe and New South Wales. A comparison was 
published in the Sydney newspapers about eighteen months © 
since, and was included in Mr. Darley’s annual report of dredging 
for 1894. Since that comparison was made, returns of work 
performed by the huge sand pump “Branckner” on the Mersey 
Bar have been published and the cost per ton (as quoted by 
Professor Warren in his annual address) has fallen to 0-89d. per 
ton. Nearly all the sand pump work of which the cost is given 
_in the paper under discussion as varying from about 13d. to 24d. 
per ton, is land reclaiming work, the material having been forced 
through pipes for distances varying from 500’ to 2,000’, whereas 
the cheap Mersey Bar work consists of sand delivered directly 
into the vessel’s hopper at two or three times the rapidity at which 
it would be possible to force it through pipes to the shore. When 
testing the hopper sand pumps “Neptune” and “Juno” at Middle 
Harbour, the 500 tons hopper like the ‘‘ Branckner’s” were filled 
in twenty minutes; but if the sand had to be discharged through 
1,500’ of piping, an average hour’s work would not exceed 200 
tons. It may be stated that at the 1895 meeting of the British 
Association, Mr. Lyster when speaking of the work done on the 
Mersey Bar gave 0°81 of a penny as the cost per ton of the 
“Branckner” work and 1-39d. as that of the smaller sand pumps- 
Mr. Allan asks for information as to how the tonnage given 18 
arrived at, and what percentage of solid material passes through 
_ the pump with the water. It has been always the usage of the 
