He gave us a good deal of curious information about the oyster.  They are obtained by means of a dredge, which consists of a flat bag, the under part made of strong iron rings looped together by stout wire.  The upper side is merely a strong netting, as it is not exposed to so much wear as the part which is drawn along the ground.  The mouth of this bag is fastened to an iron frame, with an opening about four inches deep, extending the whole breadth of the bag.  The lower part of this frame is flattened and turned forward at such an angle as to enable it to scrape the surface of the ground.  To the ends of the scraper two stout iron rods are firmly welded; these, after curving upwards, form the narrow sides of the mouth, and extend forward four or five feet, when they unite at a handle, to which a stout warp is made fast.  The free end of the bag is secured to a stout stick, which forms a convenient hold when the contents of the dredge are being turned out.  The weight of the dredge keeps it at the bottom, and but little skill is required in working it.  A good-sized boat can work two dredges at one time, one from each quarter.