WALLICH, ON APPARATUS FOR DREDGING, ETC. 3 
bag is about a yard or somewhat less in depth. The lne 
must be stout, such as is used for deep-sea fishing, for in- 
stance. A coil of this is held loosely in the left hand. The 
right grasps the ring, close to the eyelet-hole, in a horizontal 
position, and throws it with a twist, just as a quoit is thrown, 
with the mouth of the bag downwards, over the object to be 
captured ; as much line as is necessary being allowed to slip 
without check out of the left hand. 
The hoop instantly sinks, the pervious nature of the ma- 
terial forming the bag offering little or no resistance. The 
moment it has passed deep enough to embrace the object, a 
sudden haul on the hne tilts the mouth of the hoop up verti- 
cally, the sides of the bag at once collapse on each other, and 
the enclosed object is secure. So readily does this simple 
casting net answer its purpose, that at one cast in moder- 
ately calm weather it brought up a couple of open-sea 
mackerel, each a foot and a half long; and molluscs, tuni- 
caries, ascidians, and other creatures of various kinds, were, 
with ease, brought within reach. This casting net is, of 
course, equally available on the shore, off a pier, rocks, &c. 
In the drag net used by me, I found it of great advantage 
to have the hoop made also of iron, but of a triangular shape, 
instead of the ordinary round form, each angle having an 
eyelet-hole or rmg, whereupon to attach the three connecting 
intermediate lines. By lengthening one of these three lines 
somewhat, the hoop was always kept with the same angle 
downwards, and thus prevented the constant turning, and 
twisting, and jerking, attendant on the use of the ordinary 
circular hoop, whenever the ship’s rate exceeded four or five 
knots. 
For soundings, in moderate depths, up to three or four 
hundred fathoms, the following apparatus is most efficient : 
A half-inch rod of iron, four and a half feet long, is bent 
at its centre to an angle of about 150°. At one end a loop 
is formed for attachment of the line; at the other, about six 
inches is reflected on itself in the same plane as the angle 
referred to, and within this reflected portion is jammed the 
connected band of two copper cylinders, soldered strongly 
together side by side; their closed ends being of course di- 
rected outwards, their open mouths towards the angular part 
of the rod. In order to prevent regurgitation and loss of con- 
tents, a valve is formed of a plate of metal sufficiently large to 
extend right across the mouths of both cylinders. In the 
centre of this is cut a slot or aperture, to admit of vertical 
motion to the extent required, the plate being attached by a 
curved, moderately strong, flat spring to the farthest end of 
