Drill bushing to Dry battery.

Drill bushings. (Mach.) Hardening steel bushings inserted in the face of jigs and fixtures to serve as drill guides in locating holes in proper position, thus making possible rapid and accurate production of inter­changeable pa$.
Drill chuck. (Mech.) A chuck made especially for holding drills. Drilled hole. Hole finished with drill. DriB gauge. (Mach.) A flat steel plate drilled with holes of different sizes and properly marked so that the size of a drill may be easily determined by fitting it to the plate.
Drill grin«Ung gauge. (Mach.) Used for checking the length and angle of the cutting lips of the drill.
Drilling jig. (Mech.) A device very accurately made of cast or wrought iron which becomes a guide for the drilling of holes. The work is fas­tened in the jig, and the drill is guided through holes drilled in the face of the jig itself. The use of a jig makes interchangeable work easily obtainable.
Drill press. (Mach.) A geared, auto­matic-feeding machine tool used for drilling holes on metal.
Drill-press vise. (Mach.) A special vise used on the table of a drill press to hold parts being drilled.
Drill rod. (Mach.) A 90- to 100- point carbon, ground and polished tool steel finishe.d to a limit of .0005 in.
Drill socket. (Mach.) The socket which receives the tapered shank of a drill.
DriB spindle. (Mach.) The vertical spindle of a drilling machine which carried,the drill ~n~ revolves, and through whose vertical movement the feed is operated.
Drill vis~. (Mach.) A vise used on the table of a drill press for hold­ing work to be drilled.
Drip line. (Mech. Engin.) In a heating system the return pipes through which the condensation from a radiator flows back to the boiler.
Drop mold. (Arch.) A molding de­signed to prevent rain water from running down the face of a wall.
Dripstone. (Arch.) A label molding used over a window for throwing off rain; also called "weather molding".
Drive chain. (Auto.) A heavy-duty roller chain used to deliver power to the driving wheels.
Drive cord. In tuner or receiver, fine cord used in conjunction with pul­leys to drive pointer across tuning dial.
Driven. (Meeh.) The wheel, wheels, or pulleys actuated by a driver.
Drive pinion. (Auto.) Drives the large bevel gear which is connected to the differential.
Drive punch. (Leather.) A steel punch operated by blows from a hammer. Used for punching holes for eyelets, etc.
Driver. Another name for a loud­speaker, usually the term is used when the loud-speaker is coupled to a "horn" for acoustic coupling and controlled dispersion of sound.
Driver stage. Penultimate stage in power amplifier designed to feed or 'drive' the output stage. Drive screw or screw nail. A type

Drive s~aft. (Auto.) The shaft which connects the transmission to the rear axle by the use of universal joints, and carries power to the rear axle. (Mech.) Also used for a simi­lar purpose iri other machinery.
Drive unit. Loud-speaker transducer unit as distinct from enclosure or cabinet. .
Driving fit. (Mech.) One which re~ quires the blows of a hammer ,to accomplish the desired results, as in fitting a bushing to a hole.
Driving hole. (shopwk.) The setting of a part into its final position by the action of blows as from a ham­mer.
A:driving mechanism. (Shpwk..) Any arrangement of wheels, pulleys, belts, levers, etc., by which motion is communicated.
Drone. (Aero.) A pilotless plane, re­motely or automatically controlled, usually for target practice or demo­lition of enemy objectives.
Drop. (Furn.) A pendant ornament.
Drop elbow. (Plumb.) A small ell that is frequently used where gas is put into a building. These fittings have wings cast on each side to permit fastening to wall, ceiling, or fram­ingtimbers.
Drop ell. (Plumb.) An ell with lugs in the sides by means of which it can be attached to a support.
Drop-feed oiler. (Mach.) One formed in dies under a drop hammer.
Drop front. (Furn.) The front of a desk which is dropped forward for use.
Drop hammer. (Engin.) A heavy weight carried by a supporting frame which guides its travel. The weight is raised by power, then allowed to drop on the metal being forged.
Drop handle. (Furn.) Variously shaped handles which hang pendantlike.
Drop hanger. (Mach,) A shafting support atta~hed to a ceiling or un­derside of a beam.
Drop ornament. (Furn.) An orna­ment like ,an apron but not running the full width of the frame.
Dropout. (Fdry.) The loosening of the sand in the cope when the mold is closed.
Drop siding. (Arch.) A type of weath­erboard used on the exterior sur­face of frame buildings.
Drop tee. (Plumb.) A small tee hav­ing the same type wings as a drop elbow.
Drop window. (Bldg.) A window that can be lowered into a pocket be­low the still, as on trolley cars.
Dross. (Fdry.) The scurf, oxide, and other impurities which are skimmed off the top of molten metals, or which accumulate in the head or in the riser.
Drum. (Shopwk..) Usually a hollow cylinder mounted on a shaft. Fre­quently used for transmitting power by means of belts or cables.
Drum armature. (Elec.) A dynamo of motor armature having its coils wound longitudinally or parallel to its axis.
Dry battery. (Elec.) An electric bat­ tery made up of a number of dry
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