2 WALLICH, ON APPARATUS FOR DREDGING, ETC. 
the following casting net was constructed, and in the course 
of a short practice it became easy to pitch this net, quoit 
fashion, over any object within such range. 
A hoop is made of half-inch rod iron, two feet eight inches 
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a. Copper cylinders, closed at lower end. 3. Valve with curved spring. 
c. Stud for forcing up the valve plate on touching bottom. v. Lron rod. 
gE. Weight. 
Fig. 1.—Showing position of apparatus whilst sinking, the valve being 
closed. 
Fig. 2.—Showing position on reaching ground, the valve being opened. 
Fig. 3.—Showing tilting rods, as seen from mouths of cylinders. 
in diameter. At any point in this hoop a ring or eyelet-hole 
is formed by a loop of the rod, for attachment of the line. 
Sewn round the hoop is an oblong bag, the bottom of which 
is not tapered off, but allowed to remain square, the material 
called crmoline being at once the strongest, cheapest, and, 
from its open web, the best adapted for the purpose. This 
