OXIV. | A. B. PORTUS. 
through pipes and delivered at a distance of 1,500’ from the 
vessel When pumping into the hopper, a much higher per- 
centage of sand is delivered than when the material is sent on 
shore. Eighteen hundred feet may be taken as the profitable 
limit for heavy sand, while light silt with the same pump can be 
discharged at double that distance. The suction pipe of the 
“Neptune” passes through the vessel’s side at about the water 
line, and a bend outside gives it a direction towards the bow. 
Between the bend and the long suction pipe a leathern sleeve 
about 6’ in length is introduced, collapse being prevented by 
seven or eight iron rings fitted inside seven inches apart. The 
outer end of the suction pipe is carried by a strong davit, and 
the flexible leathern sleeve provides alike for lifting the pipe and 
for surging when the dredge is working in rough water. Thin 
grating bars about five inches apart are fitted across the mouth 
of the suction, which is enlarged to about 28” in diameter. 
Nise Gengred pats — with —— bo brakes 
successfully working sand pumps 
Clark, Chapman & Co. of Hull, make these siechite a speciality, 
the barrels being fitted for stud and short link chain as well as 
for wire and hemp ropes. To the forward winch the chain for 
lifting the suction pipe is led, and when working in a channel 
with the silt being discharged on shore, the same winch works 
three chains leading to anchors on each bow and to one stream 
anchor, while the stern winch deals with chains leading aft and 
upon each quarter. After the pump is started the suction pipe 
is lowered until the dial on the pump vacuum guage indicates 
about 12”, when the vessel is moved slowly ahead at a speed 
governed by signals from the man at the end of the discharge 
pipe, perhaps 1,500’ away, different coloured discs indicating # 
sufficiency of sand, or otherwise, in the water passing out of the 
_ pipe. Owing to so much sand passing through the pump there is 
necessarily much wear of surface, and the first casings were fitted 
wholly with sheathing plates, but it has been found in practice 
___ better for the sides to be made of }” steel plates, without sheath- 
