BEAM, n. [We see by the Gothic, that the word belongs to Class Bg. It properly signifies the stock or stem of a tree; that is, the fixed, firm part.]1. The largest, or a principal piece in a building, that lies across the walls, and serves to support the principal rafters.2. Any large piece of timber, long in proportion to its thickness, and squared, or hewed for use.3. The part of a balance, from the ends of which the scales are suspended; sometimes used for the whole apparatus for weighing.4. The part on the head of a stag, which bears the antlers, royals and tops.5. The pole of a carriage, which runs between the horses.6. A cylinder of wood, making part of a loom, on which weavers wind the warp before weaving; and this name is given also to the cylinder on which the cloth is rolled,as it is wove.7. The straight part or shank of an anchor.8. In ships, a great main cross timber, which holds the sides of a ship from falling together. The beams support the decks and orlops. The main beam is next the mainmast.9. The main piece of a plow, in which the plow-tails are fixed, and by which it is drawn.
10. Beam compass, an instrument consisting of a square wooden or brass beam, having sliding sockets, that carry steel or pencil points; used for describing large circles, and in large projections for drawing the furniture on wall-dials.
On the beam, in navigation, signified any distance from the ship, on a line with the beams, or at right angles with the keel.
Before the beam, is an arch of the horizon between a line that crosses the ship at right angles, or the line of the beam, and that point of the compass which she steers.
Beam ends. A vessel is said to be on her beam ends, when she inclines so much on one side that her beams approach a vertical position.
Beam-feathers, in falconry, the long feathers of a hawk's wing.