Threewire to Timber trestle

Three-wire metllod to Thumb nut

or. neutral wire and either of the outside wires of 125 volts, and 250 volts between the two outside wires. Built on the principle of two generators in series with a tap.
Three-wire method. A method of measuring the pitch diameter of screws as recommended by the U.S. Bureau of Standards. See hand­books for application.
Three-wire transformer. (Elec.) A transformer having the secondary tapped at its center in order to have equal voltage between it and either outside ends or connections, and double this voltage between the two outside or end connections.
Threshold. (Arch.) (I) The entrance to a building. (2) The plank, stone, or piece 'Of timber under a door.
Thershold of hearing. Lowest per­ceptible lei vel of sound intensity as measured in other wise silent sur­roundings. Varies with frequency, but for young people (by statistical sample) corresponds to sound pres­sure of 0.0002 dyne/cm2 at ~round 2kHz.
Threshold of pain. Level of sound intensity at which sensation be­comes painful. Usually in the re­gion of 120-130 dB above lower threshold.
Throat. (Arch.) rhe opening from the fireplace into the smoke chamber. (Mach.) The gap in the frame behind the tool in a punching machine, the size of work taken being limited by the depth of the gap.
Throttle. (Mech.) To shut off or regulate, as steam. A device for accomplishing the same.

Throttle valve. (Mech.) (I j A thin, flat disk valve placed in a pipe or opening for the purpose of clos­ing it partly or entirely, as in con­trolling the flow of air to be mixed with gas in an automobile motor. (2) A vlave in a steam line for controlling the flow.
Through bolt. (Mach.) A bolt which passes through clearance holes in the pieces to be joined. Clamping actions are secured entirely by use of a nut.
Through shake. (Wood) A shake, or separationof wood between annual rings, which extends between two faces of a timber.
Throw. (Mech.) The amount of ec­ centricity, as in the crankshaft of an engine. The throw is equal to half the length of the stroke of the piston.
Throwing. (Ceram.) The shaping of ware on a potter's wheel.
Throw out collar. (Auto.) A steel ring or collar mounted on an oilless bearing. Used to ~ngage and dis­engage the clutch.
Thrust bearing or thrust block. (Mach.) The bearing which're­ceives the longitudinal thrust or pressure of a shaft.
Thrust collar. (Mach.) A collar turned on the body of a shaft or attached to it, for the purpose of absorbing or reducing end play of the shaft or parts mounted on the shaft.
Thumb nut. (Mach.) A wing nut or one so shaped that it can be op­erated by thumb and forefinger.

Thumb plane to Timber trestle\
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Thumb plane. (Woodwkg.) A name occasionally applied to a small plane 4 or 5 in. long, having a bit about I in. in width.
Thumb screw. (Mech.) A screw to be turned with the thumb and finger.
Thumb tack. (Draw.) A sh~ pointe<! tack with relatively broad head; used by draftsmen for fastening down drawing paper. Thump. A brief, unwanted low-fre­quency noise (transient) which may occur when system power is turned On or Off, and is due to a lack of control in certain amplifier stages at that time.
Thurm. (Cabwk.) To work with saw and chisel across the grain, produc­ing in upright square members, pat­terns like those produced by turn­mg.
Tie. (Arch.) A piece inserted or at­tached to other pieces to hold them in position.
Tie beam. (Arch.)A beam which ties together or prevents the spreading out of the lower ends of the rafters of roof trusses.
Tie. dyeing. (Textile) Certain parts of the fabric to be tied are wound tightly with string to prevent the material from taking the dye. The pattern appears when the string is removed.
TI Filter. Or terrestrial interference. A circuit designed to rid satellite signals of the negative effects of microwave relay towers and other stray signals.
Tie piece. (Wood Patmkg, ) A stiffening . piece used on a pattern. It is not indi­cated on the drawing, and it need not be reproduced in the casting. Tier. To pile up one obove another, as a tier of boxes.
Tiering machine. A labor-saving ma­chine, used for stacking up or tier­ing work or materials.
Tie rod. (Auto. Mech.) The trans­verse rod connecting the front wheels of an automobile in order to permit them to act as a unit in steering.
Tie-up material. (Print.)An expres­sion which includes all the mat~­rial used in tying up composed types.
Tight fit. (Mech.) A fit made with light pressure.
Tight pulley. (Mach.) A pulley attached to its shaft; {is opposed to a loose pulley which runs free on its shaft.
Tile. (Arch.) Terra cotta, cement, or glass pieces used for roofing;. also made in artistic designs and finishes for floor and wall covering.
TilT. To move the camera up toward the ceiling (tilt up) or down toward the floor (tilt down.)
Tilt-toptable~ (Fum.)A pedestal ta­ble with the top so hinged that it can be swung from the horizontal to a vertical position.
TIM. Transient Inter Modulation..
Timber. Trees in the forest, trees when cut into logs or when sawed into large squared sizes. Specifi­cally, lumber 5 inches or more in the least dimension.
Timber trestle. (Engin.) Name ap­plied to such wooden structures as are used for carryi.ng railroad

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