Dictionary of British Scientific InstrumentsConstable Limited, 1921 - 335 pages |
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Common terms and phrases
aeroplane Anemometer angles apparatus Apparatus.-An Apparatus.-For ascertaining astronomical attached Barometer beam Beam Compass calculations Calliper Calorimeter chart Clinometer coil colours concave consisting essentially curves designed dial diffraction grating disc distance divided draughtsmen drawing electric current Electrometer Extensometer Eyepiece Galvanometer Galvanometer.-See Galvanometer Gas Analysis gases Gauge glass graduated heat horizontal Hydrometer instrument consisting instrument for determining instrument for indicating instrument for measuring invented Keratometer lens lenses liquid machine magnetic magnifying Manometer means mercury metal meter Micrometer microscope mirror mounted needle object object-glass Observatory observing optical instrument parallel PATTERN Pendulum photographic Photometer plane plate polarised light pressure Prism.-See Prism producing protractor Pyrometer Rain-Gauge reflecting refracting telescope Refractometer rotation scale screw sextant ship sight Slide-Rule Slide-Rule.-See Slide-Rule sound special form specific gravity Spectrograph Spectroscope Stadiometer stars surface surveying Telescope.-See Telescope temperature testing theodolite Thermometer.-See Thermometer tion tube vertical vessel vibrations Viscometer wire
Popular passages
Page 38 - The most useful branch of astronomy has hitherto been that which, treating of the positions and motions of the heavenly bodies, is practically applied to the determination of geographical positions on land and at sea. The Greenwich Observatory has, during the past century, been so far the largest contributor in this direction as to give rise to the remark that, if this branch of astronomy were entirely lost, it could be reconstructed from the Greenwich observations alone.
Page 70 - A kind of water-clock or an hour-glass serving to measure time by the fall of a certain quantity of water or other substance, commonly out of one vessel into another.
Page 21 - ... (1) The incident ray, the normal to the surface at the point of incidence, and the refracted ray lie in one plane. (2) The sine of the angle between the incident ray and the normal...
Page 60 - Barometer. An instrument for determining the weight or pressure of the atmosphere, and hence for judging of probable changes of weather, or for ascertaining the height of any ascent, etc.
Page 50 - Dictionary of British Scientific Instruments ISSUED BY The British Optical Instrument Manufacturers
Page 63 - An instrument for measuring the bleaching power of chloride of lime and potash.
Page 38 - The Observatory was expressly built for the aid of astronomy and navigation, for promoting methods of determining longitude at sea, and (as the circumstances that led to its foundation show) more especially for determination of the moon's motions. All these imply, as their first step, the formation of accurate catalogues of stars, and the determination of the fundamental elements of the solar system. These objects have been steadily pursued from the foundation of the Observatory...
Page 60 - Attached to this is a cistern filled with mercury, which has a stopcock and a screw adjustment. The total length of the instrument is from 12 to 15 ins., but for convenience of carriage the cistern can be detached and carried separately. The atmospheric pressure is measured by an uniform volume of air being admitted to the cistern, and compressed by the advance of the mercury to a fixed point. The readings are taken from two points, as in the Fortin barometer.
Page 102 - An instrument consisting of an adjustable mirror or reflector worked in connection with a combination of telescopes, used in trigonometrical surveys ; with it, triangles with sides over 100 miles in length can be measured.
Page 162 - A surgical instrument for measuring the external movement in the walls of the chest during respiration, as a means of diagnosis in thoracic disease.