Amide Powder: ammonium nitrate, potassium nitrate, charcoal. Has also been used in German artillery.
Ammonpulver: ammonium nitrate and charcoal. Has been used by Austrian artillery, and lately reintroduced by the Germans.
Ballistite: equal parts of nitroglycerine and soluble nitrocotton with some mineral jelly.
Cordite: the principal smokeless powder of the British Empire.
Indurite: gun-cotton and nitrobenzene. Abandoned by U.S. navy.
Neonite: a gelatinized powder. Contains nitrocellulose insoluble and soluble, metallic nitrates, and vaseline.
Noddite: a strip sporting-rifle powder containing nitroglycerine, nitrocellulose, mineral jelly.
Rottweil Smokeless Powder: a gelatined powder containing camphor and diphenylamine.
See also Grenade; Shell; Torpedo; Fireworks; Rockets.
Expo´nent. In algebra a3 denotes three a's multiplied together; an means that n of the letter a are to be multiplied. These numbers or letters placed immediately above and to the right of another number or letter are called exponents, and indicate the power to which the number or letter is raised. Exponents can be fractional or negative, in which case new interpretations can be found. On the assumption that am × an = am+n for all values of m and n, a1/n is interpreted as the nth root of a, a-n as the reciprocal of an.
Exponential Theorem. If ax = N, x is said to be the logarithm of N to the base a. There are two bases of logarithms in common use, the base 10 and the Napierian base e. The exponential theorem states that the value of ex is given by the infinite series 1 + x + x2/(1.2) + x3/(1.2.3) + ... + xn/(1.2.3..n) +, &c. Putting x equal to 1, e = 1 + 1 + 1/(1.2) + 1/(1.2.3) + 1/(1.2.3.4) +, &c. e can be expressed to any number of decimal places by working out the value of the terms on the right-hand side. It is an incommensurable number which to five decimal places is equal to 2.71828. See Logarithm.
Exports. See Foreign Trade.
Ex Post Facto, in law, a term designating something as done after and bearing upon something previously done; thus a law is said to be ex post facto, or retrospective, when it is enacted to punish an offence committed before the passing of the law.
Exposure, the situation of a building, &c., with respect to sun and wind; 'aspect' with regard to the quarter of the heavens. A house facing south-west or south-east will be found much healthier than one facing due north; and as it is also warmer, less fuel will be required for heating purposes.
Expressed Oils, in chemistry, are those which are obtainable from bodies only by pressing, to distinguish them from mineral and essential oils, which last are, for the most part, obtained by distillation.
Extension, (1) in physics and metaphysics, that property of a body in virtue of which it occupies a portion of space. (2) In logic, extension is the extent of the application of a general term, that is, the objects collectively which are included under it; thus, the word figure is more extensive than triangle, circle, or parallelogram; European more extensive than French, Frenchman, German, &c. Matter and mind are the most extensive terms of which any definite conception can be formed. Extension is contrasted with comprehension or intension.—Cf. Titchner, Text-Book of Psychology.
Extincteur (eks-tan-teur), an apparatus for the extinction of fire, consisting of a metallic case containing water and materials for generating carbonic acid. When required, the materials are brought into contact by pushing a rod which breaks a bottle containing acid, the gas mixes with the water, and the pressure generated is sufficient to project the water charged with the gas to a distance of 40 or 50 feet.