flues; and burns about 1,400 lb. of steam coal in a day
of 12 hours. There are three pumps aboard--a hand force pump for washing
boiler, a plunger pump for boiler feed, and an Evans steam pump to throw
a jet of water into the delivery hopper when digging in any very
tenacious material. All three are connected with the boiler.
Water tanks below deck serve to trim the boat and furnish a supply for
the boiler. The dredger cuts by swinging on a center spud 16 in. in
diameter, and moves forward from 8 to 10 ft. at each fleet.
The Roberts Island dredger, of which the Ajax is an improved copy,
handles steadily 700 yards per day of 12 hours, in the stiffest and most
tenacious clay in which it has been worked; and ranges from that average
to 1,500 yards per day in soft, peaty mud.
The Ajax was built by Farrington, Hyatt & Co., of the Stockton Iron
Works.
This type of dredger can be built for about $12,500, and we are informed
can be relied on for a monthly average of 26,000 yards in any material
met with in the overflowed lands near Stockton, delivered 50 ft. ashore,
at a height of 10 or 12 ft. above the ground line.--_Min. and Sci.
Press_.
* * * * *
THE FLEXIBLE GIRDER TRAMWAY.
This is an ingenious proposition for utilizing a modification of the wire
tramway system for overcoming obstacles (while retaining the ordinary
wire tramway or any light railway on other parts of the line), made by
Mr.
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