Gudgeon
2 of the 6 encyclopedias on this shelf carry an entry for Gudgeon. Both are reproduced below, so you can see where they agree and where they differ.
The Encyclopedia of Founding (1892)
The cast or wrought iron journal-piece inserted in the ends of a core-barrel, forming a horizontal shaft or axle, with collars for turning in V's or semicircles, provided on the upper edge of the trestles which constitutes a part of the core-lathe. See CORE-LATHE; CORE-BARREL. Guides for Green-sand.--See STAKES; FLASK; PIN AND COTTER. Guides for Loam-work.--These guides are of necessity somewhat temporary, and require to be well preserved during the time the mould remains separated, otherwise it is difficult to close each piece in its place correctly. If the joints are made by the spindle and sweep, let each outside edge be struck at an angle of 45 deg. with the joining surface, extending a plain face 3/4 inch in each direction. By this means both edges can be seen and felt, and any discrepancy overcome more easily than when one slides into the other by a shallow taper seating. If iron ring or plates meets loam, then make the loam to correspond, and smooth clayey sand over both, dividing at the joint, and marking a few lines thereon with a thin trowel. Should both joining edges be loam, both notches and lines may be made. See LOAM-MOULDING.
Aiton's Encyclopedia (1910)
guj'un, a small fish of the carp family. It is about eight inches long. It has a narrow, cylindrical body with a small barbel or feeler at each corner of the mouth. It is distributed throughout the fresh waters of Europe. Gudgeons keep close to the bottom of the streams or lakes. They are very easily taken with the hook and with any sort of bait. In popular usage, a gudgeon is a person easily deceived--one who swallows a bait readily.
What Has Changed in the Last Century
Aiton's 1910 description of the gudgeon as a barbelled bottom-feeder of European fresh waters, "very easily taken with the hook," still holds; the fish is Gobio gobio, and molecular work since the 1990s has split what was treated as one wide-ranging species into a cluster of regional ones, so populations in Spain and eastern Europe now carry their own names. The 1892 foundry entry describes a world that has largely vanished: hand loam-moulding with spindle and sweep, and the core-lathe with its gudgeons resting in V-notched trestles, survived into the mid-twentieth century for very large castings but is now a specialist or heritage craft, displaced by machine-made cores and resin-bonded sand. The word itself moved into the engine room, where a gudgeon pin is the pin joining piston to connecting rod, and onto boats, where gudgeons take the rudder pintles. The figurative gudgeon, "a person easily deceived," has faded from everyday English since 1910.
Written for this edition, 2026.