Fastened to the frame are iron handles, to which a rope or iron chain is attached.Ī machine for clearing the beds of canals, rivers, harbors, etc. The net is usually composed of heavy twine, but sometimes of iron chainwork, and is attached to the frame by holes near the inner edges. As generally constructed, the frame is transversely oblong, generally about three times as long as wide, with straight ends and slightly inclined sides, having the outer edges sharp to serve as scrapers. It consists principally of a frame of iron and a net which is attached to the frame.
A drag-net for taking oysters, etc.Īn apparatus for bringing up marine animals, plants, and other objects from the bottom of the sea for scientific investigation. Any instrument for bringing up or removing solid substances from under water by dragging on the bottom.
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