Part 252

Tox`i*co*gen"ic (?), a. [See Toxic, and -genic.] (Physiol. & Med.) Producing toxic products; as, toxicogenic germs or bacteria.

Tox"oid (?), n. [Toxin + - oid.] (Physiol. Chem.) An altered form of a toxin, possessing little or no toxic power.

Trace (?), n. (Mech.) A connecting bar or rod, pivoted at each end to the end of another piece, for transmitting motion, esp. from one plane to another; specif., such a piece in an organ-stop action to transmit motion from the trundle to the lever actuating the stop slider.

Trac"er (?), n. 1. A person engaged (esp. in the express or railway service) in tracing, or searching out, missing articles, as packages or freight cars.

2. An inquiry sent out (esp. in transportation service) for a missing article, as a letter or an express package.

Tra"cer*y, n. A tracing of lines; a system of lines produced by, or as if by, tracing, esp. when interweaving or branching out in ornamental or graceful figures. "Knit with curious tracery." Burns.

||Tra`che*i"tis (?), n. [NL. See Trachea; -itis.] (Med.) Inflammation of the trachea, or windpipe.

||Tra*cho"ma (?), n. [NL., fr. Gr. &?; roughness, fr. &?; rough.] (Med.) Granular conjunctivitis due to a specific micrococcus. -- Tra*chom"a*tous (#), a.

Track"age, n. (Railroads) Lines of track, collectively; as, an extensive trackage.

Track"lay`er (?), n. (Railroads) Any workman engaged in work involved in putting the track in place. [U. S. & Canada] -- Track"lay`ing, n.

Track"man (?), n.; pl. - men (&?;). (Railroads) One employed on work on the track; specif., a trackwalker.

Track"walk`er (?), n. (Railroads) A person employed to walk over and inspect a section of tracks.

Track"way` (?), n. Any of two or more narrow paths, of steel, smooth stone, or the like, laid in a public roadway otherwise formed of an inferior pavement, as cobblestones, to provide an easy way for wheels.

Trac"tion*al (?), a. Of or relating to traction.

Traction wheel. (Mach.) (a) A locomotive driving wheel which acts by friction adhesion to a smooth track. (b) A smooth-rimmed friction wheel for giving motion to an endless link belt or the like.

Tract"or (?), n. An aëroplane flying machine having one or more tractor screws.

{ Tractor screw or propeller }. (Aviation) A propeller screw placed in front of the supporting planes of an aëroplane instead of behind them, so that it exerts a pull instead of a push. Hence, Tractor monoplane, Tractor biplane, etc.

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Trade name. 1. (a) The name by which an article is called among traders, etc.; as, tin spirits is a common trade name in the dyeing industry for various solutions of tin salts. (b) An invented or arbitrary adopted name given by a manufacturer or merchant to an article to distinguish it as produced or sold by him.

2. The name or style under which a concern or firm does business. This name becomes a part of the good will of a business; it is not protected by the registration acts, but a qualified common-law protection against its misuse exists, analogous to that existing in the case of trade-marks.

Traf"fic mile. (Railroad Accounting) Any unit of the total obtained by adding the passenger miles and ton miles in a railroad's transportation for a given period; -- a term and practice of restricted or erroneous usage.

Traffic mile is a term designed to furnish an excuse for the erroneous practice of adding together two things (ton miles and passenger miles) which, being of different kinds, cannot properly be added.

Hadley.

Trail"er, n. A car coupled to, and drawn by, a motor car in front of it; -- used esp. of such cars on street railroads. Called also trail car.

Trail"ing edge. (Aëronautics) A following edge. See Advancing edge, above.

Trail rope. (Aëronautics) Same as Guide rope, above.

Train (?), n. 1. A heavy long sleigh used in Canada for the transportation of merchandise, wood, and the like.

2. (Mil.) The aggregation of men, animals, and vehicles which accompany an army or one of its subdivisions, and transport its baggage, ammunition, supplies, and reserve materials of all kinds.