Bori1lg to Box girder

Boring. (Mach.) Making of finishing circular holes in wood or metal.
Boring bar. (Mach.) A sliff cylinder bar provided with a cUllerhead; used on lathes, drill presses, and other machines for boring cylinders, etc.
Boring machine. (Mach.) A machine for boring cylinders, bosses, bed rings, and the like. "
Boring mill. (Mach.) An upright ma­chine tool w~th revolving table which carries the work. The tool rest is car­ried on a crossrail. Many jobs are more easily "set up" on a boring mill than on a lathe.
Boring tool. Brace, bit and similar tools for wood; cutters for metal, includ­ing a large number of types.
Boron. (Chern.) Obtained by electroly­sis. Resembles silicon. Used to harden steels and in compounds as fluxes and deoxidizing agents.
Boron carbide. (Chern.) A fine, black, crystalline powderofhardness nearly equalto that of the diamond. tJsed as an abrasive.
Bort.A name applied to diamonds that are used of abrasive purposes.
Boss. (Arch.) An ornament usually carved, forming the keystone at the intersection of the ribs of a grained vault. (Mach.) (I) The center or hub of a wheel; (2) a circular disk cast on or attached to some mechanical part.
Bossing stick. (Plumb.) A wooden tool for shaping lead for tank lining.
Boston hip roof. (Arch.) Formed by laying double row of shingles or slate lengthwise along the hip;joints must be securely made to obtain a watertight job.
Botany. The science of plant life.

Botch. To do a poor job in a slov­enly and un workmanlike manner; also, a spoiled job.
Bottled. (Pr;;lt.) Type which is wider at the bottom than at the top, due to an imperfect casting, is said to be "bottled."
Bottom-anchored core. (FdlY.) A core anchored to the bottom of a mold to prevent any tendency to float when the mold is poured. Its use should be avoided if possible.
Bottom board. (Fdry.) The board or plate that is placed on top of the drag and fastened there before rolling it over. It then serves as the bottom of the mold during the remaining molding and casting operations.
Bottom clearance. (Gear.) The diffe­rence between dedendum and addendum which provides for the clearance between the top and root of gear teeth when in mesh.
Bottom rail. (Arch.) The lowest hori­zontal member of a door or of a window sash.
Bottom stake. (Sheet-Met. Wk.) An
upright bar with the working edge . at the upper end.
Bott stick. (Fdry.) A light iron rod 5
or 6 fl. long with a disklike ex­pansion at one end. A stopping bar on which a lump of clay is gathered to be used in stopping the flow of metal from the cupola.
Bounce. Light reflected off wall or ceiling.
Bouncing. A term referring to the trusty system employed by many compact multi tracker owners to get more information on to any one cassette or reel to tape. Sim­

Box girderply, it means transferring the in­
formation of one track onto an­other in addition to any new sig­nals. Commonly, it is p'ossible to record ten different lines of music of iriformation on a compact multitracker which has full 4- T capability. Less scrupulous mem­bers of the profession call the tech­nique 'ping ponging'. Bouncing will result, in the majority of cases, jn a loss in quality on initial tracks, as the information will be subject more than once to the dreaded noise performance of a m.;ltitrack recording sys~m.
Bouncing tracks. A term synonymous with "ping pong".
Boundary. A limiting or dividing line or mark.
Boundary light. (Aero.) Anyone of the lights designed to indicate the limits of the landing area of an . airport or landing field.
Boundary marker. (Aero.) A painted cone, solid circle, disk, or other device used to mark .the boundary of the available landing area on an airport or lan<iing field.
Bourdon tube. (Auto. Mech.)A sealed tube containing a highly volatile gas, the expansion of which con­trols a registering needle on a graduated dial.
Bourgeois. (Print.) An old designa­tion of a type size equivalent ap­proximately to 9 point.
Bow. (Arch.) Any projecting part of a building in the form of an arc or of a polygon.
Bow compass. (Draft.) A small com­pass used by draftsmen. Positive adjustment is obtained by means of a screw which connects the two legs.

Bowheavy. (Aero.) The condition of an airship which, when at rest in still air, trims with its axis inclined down by the bow. The term "bow­heavy" is preferred to "nose-heavy" in describing airships.
Bow pen. (Draft.) A compass used -for inking small arcs or circles; as in other bow instruments adjust­ment is made by means of a screw connecting the legs.
Bow pencil. (Draft.) A drawing in­strument used in penciling small arcs or circles. (See Bow Com­pass and Bow Pen).
Bow saw. (Carp.) A saw with a thin narrow blade held in tension by the leverage obtained through the twisting of a cord, or by means of rods and turnbuckle.
Bow window. (Arch.) A window placed in a bow, i.e., any project­ing part of a building which is in the shape of an arc or of a polygon.
Box annealing. (MetaL) A method of annealing steel by heating it in a closed metal box.
Boxboard. (Papermkg.) A thick card­board with folding qualities used for making boxes.
Box column. (Arch.) A built-up hol­low ferrule usually of square sec­tion used in porch construction.
Box connector. (Elec.) A kind of hollow ferule with nut, used to attach ends of cable to a box.
Box frame. (Arch.) A window frame contianing boxes for the sash weights.
Box girder. (Engin.) A built-up girder consisting of two parallel I
beams with plates joining them riveted upon top and bottom.
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