Popular Lectures on Science and Art: Delivered in the Principal Cities and Towns of the United States, Volume 1Greeley & McElrath, 1846 - Science |
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Page 9
... Distance of the Stars proved by the Earth's annual Motion - Observations made at Greenwich . - Bessel's Discovery of the Parallax . - The conse- quent Distance of the Stars - Illustrations of the Magnitude of this Distance . - The ...
... Distance of the Stars proved by the Earth's annual Motion - Observations made at Greenwich . - Bessel's Discovery of the Parallax . - The conse- quent Distance of the Stars - Illustrations of the Magnitude of this Distance . - The ...
Page 8
... Distance beyond which it was inaudible. — Distance at which \ other Sounds have been heard. — Effects of Heat, Cold, Wind, &c- — On the Transmission of , Sound. — Thunder heard when no Cloud was visible. — Hypothesis of the Cause of ...
... Distance beyond which it was inaudible. — Distance at which \ other Sounds have been heard. — Effects of Heat, Cold, Wind, &c- — On the Transmission of , Sound. — Thunder heard when no Cloud was visible. — Hypothesis of the Cause of ...
Page 20
... distance of the earth from the sun is generally stated as a hundred millions of miles . This is easily re- membered . Nor is it of any real importance for the objects of general information , that the real distance is more ex- actly ...
... distance of the earth from the sun is generally stated as a hundred millions of miles . This is easily re- membered . Nor is it of any real importance for the objects of general information , that the real distance is more ex- actly ...
Page 51
... distance from the object to which we direct our view ; it will enable us to approach it within a certain limit of distance , and to behold it as we should do without a telescope at the lesser distances . But , strictly speaking , it ...
... distance from the object to which we direct our view ; it will enable us to approach it within a certain limit of distance , and to behold it as we should do without a telescope at the lesser distances . But , strictly speaking , it ...
Page 52
... distance without a telescope at all . Such is the extent of the aid which we should derive from the telescope . Now , let us see what this aid would effect . Take the case of the moon , the nearest body in the universe to the earth ...
... distance without a telescope at all . Such is the extent of the aid which we should derive from the telescope . Now , let us see what this aid would effect . Take the case of the moon , the nearest body in the universe to the earth ...
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Common terms and phrases
acid alkali apparent magnitude appear Arago ascertained astronomical atmosphere attraction barometer body cause centre circumstances clouds color comet conductor consequently degree diameter direction discovery disk distance diurnal motion dogstar earth eclipse effect electricity electrified equal experiments fact fluid force full moon glass globe greater Halley's comet heat height hemisphere Herschel hundred inch increased interval John Herschel Jupiter less Leyden jar light liquid luminous lunar lunar phases magnitude matter mercury metallic meteors millions of miles motion move nature negative object observed orbit pass phenomena physical pile planet pole position present principle produced proportion quantity radiation rays reflected rendered round the sun Saturn seen Sir William Herschel solar solar system space stars substances sun's supposed supposition surface telescope temperature theory thermometer thunder tides tion tricity tube vapor velocity vessel visible Voltaic Voltaic pile weather wire zinc
Popular passages
Page 117 - To determine the question, whether the clouds that contain lightning are electrified or not, I would propose an experiment to be tried where it may be done conveniently.
Page 21 - The square of the hypotenuse of a right-angled triangle is equal to the sum of the squares of the other two sides.
Page 117 - ... a wire down the outside of the building into the ground, or down round one of the shrouds of a ship, and down her side till it reaches the water? Would not these pointed rods probably draw the electrical fire silently out of a cloud before it came nigh enough to strike, and thereby secure us from that most sudden and terrible mischief?
Page 117 - The horizontal motion of the scales over the floor, may represent the motion of the clouds over the earth ; and the erect iron punch, a hill or high building ; and then we see how electrified clouds passing over hills or high buildings at too great a height to strike, may be attracted lower till within their striking distance. And, lastly, if a needle fixed on the punch with its point upright, or even on the floor below the punch, will draw the fire from the scale silently at a much greater than...
Page 116 - Take a pair of large brass scales, of two or more feet beam, the cords of the scales being silk. Suspend the beam by a packthread from the ceiling, so that the bottom of the scales may be about a foot from the floor; the scales will move round in a circle by the untwisting of the packthread. Set the iron punch on the end upon the floor, in such a place as that the scales may pass over it in making their circle ; then electrify one scale by applying the wire of a charged phial to it. As they move...
Page 118 - With this apparatus, on the appearance of a thunder-gust approaching, he went out into the commons, accompanied by his son," to whom alone he communicated his intentions, well knowing the ridicule which, too generally for the interest of science, awaits unsuccessful experiments in philosophy.
Page 244 - Saturn, yet micrometrical measurements of extreme delicacy" have demonstrated that the coincidence is not mathematically exact, but that the centre of gravity of the rings oscillates round that of the body, describing a very minute orbit, probably under laws of much complexity.
Page 110 - Electricity, which was more generally read and admired in all parts of Europe than these letters. There is hardly any European language into which they have not been translated...
Page 117 - ... feet, pointed very sharp at the end. If the electrical stand be kept clean and dry, a man standing on it, when such clouds are passing low, might be electrified and afford sparks, the rod drawing fire to him from a cloud.
Page 167 - ... domain of physical science, and clothes the natural philosopher with powers denied to the political and moral inquirer, yet foreknowledge is eminently the privilege of the astronomer. Nature has raised the curtain of futurity, and displayed before him the succession of her decrees, so far as they...