tension (tenshon)

[F. tension = Sp. ten sion = Pg. tensão = It. tensione, Voice being raised by stiffe tension of the larynx. Holder, Elements of Speech, p. 74. 2. In mech., stre , or the force by which a bar,' rod, string, or the like is pulled when forming part of any system in equilibrium or in motion. R. S. Ball , Exper. Mechanics, p. 232. 3. In physics, a constrained condition of the particles of bodies, arising from the action of antagonistic forces, in which they tend to return to their former condition; elastic force. Tension may be present in a solid body, and also in a liquid in the case of surface-tension (which see), but not in a gas. What is commonly called the tension of a gas is properly its pre ure simply-due, according to the kinetic theory of gases (see gas , 1), to the innumerable impacts of the moving molecules against the confining surface; good writers avoid the use of tension in this sense. 4. In statical elect., the mechanical stre acro a dielectric, due to accumulated charges, as in a condenser; hence, the same as surface - density (the amount of electricity at any point of the surface of a charged conductor); more commonly used, in dynamical electricity, to mean about the same as difference of potential: thus, a current of high tension is popularly a current of Rom. of the Rose, 1. 3373. high electromotive force. A body is said to have a IMG:content-0094.jpg:[graphic] tension high-tension charge, or a charge of high-tension electricity, and a conductor to carry a high-tension current, when the stre in the medium surrounding the body or the conductor is high. In magnetism, an electromagnet surrounded by a coil of many turns and high electrical resistance was called by Henry a tension magnet. Potential is the scientific term for the electrical condition for which the word tension has been used. Jour . Franklin Inst ., CXXV. 57. 5. Mental strain, stretch, or application; strong or severe intellectual effort; strong excitement of feeling; great activity or strain of the emotions or the will. When the tension of mind relating to their daily affairs was over, they sunk into fallow rest. Mrs. Gaskell , North and South, xl. In desiring the mind is in a state of active tension. J. Sully , Outlines of Psychol., p. 579. The states of tension have as positive an influence as any in determining the total condition, and in deciding what the psychosis shall be. W. James , Prin. of Psychol., I. 235. 6. A strained state of any kind: as, political tension; social tension.-7. An attachment to a sewing-machine for regulating the strain of the thread. It is made in a variety of forms, the aim being in all cases to put a pre ure on the thread to prevent it from running from the spool too freely, and to adjust the strain on the thread to the thickne of the cloth.Initial tension. See initial. Surface tension. See surface-tension. IMG:content-0095.png:[blocks in formation] as tension-bridge (ten's hon-brij), n. 1. Same as bowstring-bridge. E. H. Knight. -2. A form of bridge formerly used for street spans, consisting e entially of wooden pieces anchored at the ends, and strained to maintain them nearly level as po ible. E. H. Knight. tension-fuse (ten's hon-fūz), n. See fuse2. tension-member (ten's hon-member), n. A rod, bar, or beam forming a member of a frame, tru , beam, or girder, and serving to bear the tensile strain.