A Plea for Reflectors, Being a Description of the New Astronomical Telescopes with Silvered-glass Specula: And Instructions for Adjusting and Using ThemJ. Browning, 1876 - 78 pages |
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Common terms and phrases
achromatic adapted adjustment Alt-azimuth stand Andromeda angle aperture Automatic Electric Lamp battery Best ditto brass Browning's Automatic clamp declination circle diagonal mirror diagrams dial discs dispersive power distilled water Ditto ditto divided double stars equatorial mounting Extra Eye-pieces eye-piece favourable field of view flexure focus Glass Specula Astronomical Greenwich and Edinburgh hour circle inch speculum inches diameter Insulated Spark Apparatus ivory scale JOHN BROWNING Jupiter Lantern LARGE ALT-AZIMUTH large aperture Lens magnifying Mahogany Majesty's Government Micrometer minute Moon Nebula night object glass Observatories of Greenwich observer OPTICAL AND PHYSICAL ounces parabolising performance PHYSICAL INSTRUMENT MAKER plane plate Polar Axis polished position Price prism R. A. PROCTOR reflecting Prism reflecting telescopes Reflector refractors rings Royal Observatories screw motions seen SILVERED GLASS SPECULA Slides Solar solution Spectroscope Spectrum Analysis SPECTRUM APPARATUS speculum metal spherical curve steady T. W. WEBB tangent screw temperature Thermometer unsteady verniers ΙΟ
Popular passages
Page 48 - SCHELLEN'S SPECTRUM ANALYSIS, in its application to Terrestrial Substances and the Physical Constitution of the Heavenly Bodies. Translated by JANE and C. LASSELL; edited, with Notes, by W. HUGGINS, LL.D. FRS With 13 Plates (6 coloured) and 223 Woodcuts. 8vo. price 28s. CELESTIAL OBJECTS for COMMON TELESCOPES.
Page 30 - Add distilled water until the bulk reaches 15 ounces, and add, drop by drop, some of solution A, until a grey precipitate, which does not re-dissolve after stirring for three minutes, is obtained, then add 15 ounces more of distilled water. Set this solution aside to settle. Do not filter. When all is ready for immersing the mirror, add to the silvering solution 2 ounces of solution C, and stir gently and thoroughly.
Page 30 - A into a glass vessel capable of holding 35 fluid ounces. Add, drop by drop, stirring all the time with a glass rod, as much liquid ammonia as is just necessary to obtain a clear solution of the grey precipitate first thrown down. Add 4 ounces of solution B.
Page 30 - ... of turpentine to secure adhesion. Let the whole rest until the pitch is cold. To clean the Speculum. — Place the speculum, cemented to the circular block, face upwards, on a level table ; pour on it a small quantity of strong nitric acid, and rub it gently all over the surface with a brush made by plugging...
Page 50 - BROWNING'S NEW LARGE AUTOMATIC ELECTRIC LAMP. In this Lamp both carbons are moved by the electricity of the battery employed (without the aid of clockwork) ; the light remains uniform in height, and more steady in action than any of the expensive regulators previously introduced. Any number, from 20 to so-quart Grove's Cells, or 2-quart Bunsen's, maybe used with this Lamp.
Page 30 - Melt some pitch in any convenient vessel, and, having placed the wooden block, face upwards, on a level table, pour on it the fluid pitch, and on the pitch place the back of the speculum, having previously moistened it with a little...
Page 51 - Apparatus, at a very low price, for projecting the spectra of metals, or the absorption bands of liquids, on a screen. The Apparatus comprises an Automatic Electric Lamp and Lantern, with slit...
Page 31 - ... until the pitch is cold. To clean the Speculum. — Place the speculum, cemented to the circular block, face upwards, on a level table ; pour on it a small quantity of strong nitric acid, and rub it gently all over the surface with a brush made by plugging a glass tube with pure cotton wool.
Page 45 - Fraunhofer lines, the bright lines of the metals and gases, and the absorption bands in coloured gases, crystals or liquids. Price, with Plain Slit ., ,, Adjustable Slit, &c.( in Morocco Case ... „ ,, Achromatic Lens, &c., in Morocco Case...
Page 44 - A PLEA for REFLECTORS ; being a Description of the New Astronomical Telescopes, with silvered glass specula, and instructions for using and adjusting them, with many Illustrations and Coloured Frontispiece of Jupiter.