Terminology

Leonardo, Vol. 12. p. 326. Pergamon Press 1979. Printed in Great Britain TERMINOLOGY The terms defined below were selected from artists’ Articles and Notes published in the previous issue of Leonardo. Each definition is followed by an indication of the volume and page of Leonardo on which the term first appears. The terms were not found in the art dictionaries among the dictionaries listed in Leonardo 12,65(1979)or they are used in a new sense. Some are terms that have been carried over into the field of art from the natural and social sciences, from mathematics and from technology . Numbers in brackets, e.g. (3, 171, refer to the dictionaries mentioned above. The definitions are not presumed to be unassailable. The editors would, therefore, welcome the comments of readers on the definitions presented. 955. Chloroform(inchemistryFA colorless, volatile, heavy, toxic organic liquid that is used in chemical technology as a solvent. Sometimes it is used as a general anesthetic. (12, 222; [181) 956. Colloidal solution (inchemistrykA heterogeneous dispersion of finely divided particles (size range 5 x 1 0 - 7 to 5 x 10-4cm) of a substance in a fluid. The properties of a colloidal solution are distinct from those of a homogeneous, molecular solution. For example, colloid4 particles in suspension usually scatter light, whereas molecules in solution do not, and colloidal particles in liquids exert negligible influenceon the freezing and boiling points, unlike molecules in solution. (12, 222; [12. 151) (cf. Terminology, Leonard0 10,237 ( I 977):colloidal chemistry) 957. Explosive engraving (in visual a r t t T e r m coined by V. Molin for the technique for producing a fine-grained imprint on a metal surface by means of a detonation for use in making prints. The imprints, for example of leaves, of lines drawn with special fluids on paper and of particles suspended in a viscous layer, are made on a metal plate by detonating a sheet of explosive superimposed on the object in contact with the plate. The technique is a variant of the technique of explosive forming used in industry. (12, 222) 958. Horsepower,HP (inrechnologyFA unit of power. For example, it indicates the work done per unit time by a heat engine or an electricmotor. In the British system one horsepower is the work done per unit time when a weight of 550Ibis lifted at a rate of one ft per sec. In the metric systemit is equal to 776watts. (12, 222; [181) (cf. Term 963:power) 959. Lathe (in technology)-A machine in which a piece of metal, wood, plastic, etc. is mounted and rotated about a horizontal axis, and a cutting tool thrust against the material traverses laterally at adjustable distances from the axis to carve the desired rotationally symmetrical form. (12, 187; [3, IS]) 960. Marine plywood (in wood technologybPlywood consisting of sheets of wood cemented together using a waterinsoluble adhesive. It is employed in the construction of boats and of other objects intended for outdoor use. (12, 190) 961. Nitroglycerin(inexplosives technology)-A heavy, oily, highlysensitiveexplosiveliquid. It is handled more safelywhen it is absorbed in a solid, as in the case of dynamite. (12,222; [18]) 962. Phosphor bronze (in metal technologytAn alloy of copper, tin and phosphorus that is tough, hard and elastic. It is commonly used for making bearing surfaces and springs of specializedshapes. (12, 190; [151) 963. Power(inphysics)-The time rate at which work isdone or energy emitted or transferred. [I81 964. SilverSteel (inmetal technologyFA fine steel contain- .ing a small amount of silver. (12, 189; [17]) 965. Styrofoam, Thermocole (in plastics technology)Proprietary names for the plastic polystyrene in the form of a rigid foam. It isused for insulation, theatrical decor, etc. (12,194) (cf. Terminology, Leonardo 4, 288 (1971):polystyrene) 966. Thermocole(inplasticsrechnology~(l2,194)(cf.Term 965: Styrofoam) 326 ...