A Treatise on Industrial Photometry with Special Application to Electric LightingD. Van Nostrand Company, 1894 - 324 стор. |
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A Treatise on Industrial Photometry with Special Application to Electric ... Adrien Palaz Повний перегляд - 1894 |
Загальні терміни та фрази
absolute standard acetate of amyl amperes amyl lamp angle Antwerp apparatus arc-lamps Argand Argand burner axis azimuths brightness burner calculated candle power candle-burner carbon carburetted carcel lamp cent coefficients color combustion constant consumption corresponding Crova curve determined diameter diaphragm diffuser direction disc distance efficiency electric employed energy equal equation exact filament flame formula Foucault screen give given glass grams height horizontal intensity I₁ incandescent lamp inclination intensity of illumination Krüss lens Liebenthal light emitted light received luminous intensity maximum mean spherical intensity method mirror movable Nicol prism normal observer obtained paraffine pencil pentane petroleum petroleum lamp photometric bench photometric measurements photometric standard placed plates platinum polarized prism quantity of light radiants ratio reflection source of light spectrum spermaceti stearine sufficient surface temperature tint tion tube varies vertical Violle voltaic arc watts per candle wave-length wick Wollaston prism
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Сторінка 318 - ... of tests. The results obtained are given in the accompanying table. In the majority of cases the numbers given are approximate only, as there seemed no object in aiming at great accuracy. The first four surfaces referred to in the table, viz., thick white blotting-paper, white (rough) cartridge-paper, tracingpaper, and tracing-cloth, were, however, carefully tested, and the numbers obtained represent the mean of many observations. TABLE I.
Сторінка 68 - In ordinary light, the vibrations take place in all directions in a plane at right angles to the ray, as shown in Fig.
Сторінка 212 - ... observations, and, secondly, because the formula obtained from the differential equation on that supposition agrees with observations within the temperature ranges in which it has been tested. Treating a therefore as independent of the temperature we get in which the heat of dilution is expressed as the sum of two terms, one of which is proportional to the absolute temperature, the other independent of temperature. Such a relation could not be expected to hold for all temperatures, but within...
Сторінка 163 - ... normal direction by a square centimeter .of surface of molten platinum at the temperature of solidification. The practical unit of white light is the total quantity of light emitted normally by the same surface.
Сторінка 163 - The unit of each kind of simple light is the quantity of light of the same kind emitted in a normal direction by a square centimeter of surface of molten platinum at the temperature of solidification. The practical unit of white light is the quantity of white light emitted normally by the same source.
Сторінка iv - In 1924 he received the degree of doctor of science from the University of Manchester.
Сторінка 226 - In truth, the voltaic arc is a portion of the electric circuit, possessing the properties of all other parts of the same circuit. The molecules, swept away from point to point, constitute...
Сторінка 318 - Tracing paper ... 22 7'0 76-0 1 05 'о ( )rdi' ary mirror... 82 Ordinary foolscap 50 to 70 Tissue paper (one thickness 40 Tissue paper (two thicknesses 55 Yellow wall-paper 40 Blue paper 25 Dark brown paper 13 Yellow painted wall 20...
Сторінка 317 - ... to have stopped. A little consideration will show that the effect is precisely and identically the same as though the end of the positive carbon were flat. No tilting of an incandescent or other luminous surface can make it brighter ; and, on the other hand, if it is covered with a thin, imperfectly transparent layer, as in the case of the atmosphere of the sun, the edge will appear less bright than the middle of the disc. The quantity of light...
Сторінка 10 - Fechner's psycho-physical law the intensity of the sensation is proportional to the logarithm of the excitation.