Travelling crane to Tripoli

Travelling crane to Trigger
volcanic districts, used in the mak- . ing of a hydraulic cement.
Travelling crane. (F dry.) A crane op­erated by steam or electric power, and so geared tha it may travel lon­gitudinally or transversely. The crane, usually of the overhead type, is m,ounted on a cross beam whose ends are carried on .parallel rails.
Treacle stage. (Plast.) A thermoset­ ting resin in liquid from.
Tread. (Arch.) The flat portion of a step, as that portion on which the foot is placed when mounting the stairs. Treble. HF and of audio spectrum, above 2 - 3 kHz. In musical nota­tion, bottom line on the treble clef is E(329.63 Hz).
Treadle. (Mach.) That portion of a machine operated by the foot.
Trefoil. (Arch.) A three-lobed orna­mental unit.
Treillage. A trellis; latticework for sup­porting vines.
Trellis. (Arch.) An ornamental lattice made up of wooden strips to sup­port vines; a summerhouse or the like made of latticework.
Tremolo. Rapid iteration of a nore, or variation of amplitude. Not" to be confused with vibrato.
Trench. (Engin.) A long narrow exca­vation in the ground, as a trench dug for the laying of pipes. Trend. General tendency.
Trepan. (Mach.) To cut a circular groove around a hole. T rest. The tool support on a wood turning lathe. Also a support for work being ground by an abrasive wheel.

Tresde. (Arch.) Usually a horizontal beam with four braced legs, used in pairs to support a horizontal board. (Engin.) Timberwork sup­porting a road or railroad over a depression. (Furn.) A braced frame forming the support of a table top. (Uphol.)A sawhorse with a winder top with a stuffed roll around the outer edges. .
Trestle table. (Draw.) A large draw­ing board carried on trestles.
Triangle. (Geom.) A. figure having three sides and three interior an­gles. A right triangle is one having one right angle; an equilateral tri­angle has equal sides and angles. Area = base x half perpendicular height.
Triangular scale. (Draw.) A drafts­man's scale having three faces and six graduated edges, one edge with full-size measurements and the oth­ers with various reductions in scale.
Triangular truss. A very pOJ:}ular truss for short spans especially for roof support.
Triangulation. (Surv.) The use of a series of triangles formed by lines which connect points of observa­tion, for measuring distances on, and areas of, land and water.
Trickle charge. (Elec.) A rectifier changing alternating current to di­
rect current, and delivering the. same to a storage battery for 24 hours per day, usually at a very minute rate.
Trifiorium. (A rch.) The space between the sloping roof over the aisle and aisle vaulting in a church.
Trigger. In a music synthesier, the

Triglyphs to Tripoli

trigger is single voltage pulse created when any key on the keyboard is depressed. The trigger in turn causes other circuitry to operate.
Triglyphs. (Arch.) The flats of the Doric frieze which contain three vertical channels.
Trigonometry. (Math.) The science of measuring the sides and angles of triangles.
Trim. (Arch.) Ornamental parts of wood or metal; used to cover the joints between jambs and plaster wall around a door or window. (Papermkg.) The greatest width of finished paper which can be made on a paper machine allowing for trimming off the two deckle edges.
Trim (airplane). (Aero.) The altitude with respect to wind axes at which balance occurs in rectilinear flight with free controls. (Arch.) Moldings and other finishings about a door,
window, etc., either internal or ex­ternal.
Trim angle. (Aero.) The angle be­tween the horizontal and the lon~ gitudinal base line of a seaplane float or flying-boat hull. It is posi­tive when the bow is higher than the stern.
Trimmer. Small adjustable capacitor, usually preset to 'trim' RF circuits.
Trimmer arch. (Arch.) The rather flat arch such as is used to support a hearth.
Trimmers. (Arch.) (See Trimming joists. )
Trimming dies. (Mach.) Dies used to remove the superfluous metal left around the edges of many kinds of drawn or formed work.
Trimming joist. (Arch.) A joist which supports a header joist. Trim size. (Bookbndg.) The size of
the bound and trimmed page.
Triode. Valve with three electrodes; cathode, control gride anode.
Trip hammer. (Mach.) A power hammer operated by a tripping mechanism which causes the ham­mer to drop.
Triphibian. (Aero.) An airplane equipped with a gear for taking off and landing on land, water, snow or ice.
Triplane. (Aero.) An airplane with three main supporting surfaces, one above another.
Triple case. (Print.) A type storage case spaced to hold three fonts of type.
Triple play. Magnetic recording tape one third the thickness of standard paly.
Triplex steel. (Metal.) A steel pro­duced by a combination of the. Bessemer, basic open hearth and the electric processes.
Tripod. A three-legged stand on top of which a camera is mounted. Tripoli. Rottenstone or decomposed