
	Where results make sense

Topic: Crookes tube

	Crookes Tube - Picture - MSN Encarta
		Sir William Crookes constructed this forerunner of the modern television picture tube in the 1870s to investigate the properties of cathode rays.
		When the tube is evacuated and a high voltage applied, one end of the tube glows, caused by cathode rays (now known to be electrons) striking the glass.
		The major differences are that a CRT uses a heated cathode to increase the number of electrons, while the Crookes tube does not, and the CRT has extra electrodes to focus and deflect the beam as it travels toward the screen.
	encarta.msn.com /media_461556463/Crookes_Tube.html (112 words)

	Crookes tube - Wikipedia, the free encyclopedia
		The Crookes tube is an evacuated glass cone with 3 node elements (one anode and two cathodes).
		It is an invention of the 19th century scientist William Crookes and is an evolutionary development of the earlier Geissler tube.
		In this way, the tube was eventually developed as the display portion of the oscilloscope (a diagnostic and display device for use in electronics).
	en.wikipedia.org /wiki/Crookes_tube (493 words)

	Crookes tube - HighBeam Encyclopedia (Site not responding. Last check: 2007-11-03)
		Crookes tube device invented by Sir William Crookes (c.1875) consisting essentially of a sealed glass tube from which nearly all the air has been removed and through the walls of which are passed two electrodes.
		When a high voltage is applied between the two electrodes, electrons are emitted from the cathode and are accelerated toward the anode.
		The Crookes tube was used by Crookes in a number of experiments and was later used in experiments leading to the discovery of X rays by W. Roentgen (1895) and of the electron by J. Thomson (1897).
	www.encyclopedia.com /doc/1E1-crookest.html (250 words)

	Crookes Mineral Fluorescence Tube (Site not responding. Last check: 2007-11-03)
		One of the most popular forms of such tubes is the fluorescence tube, a vacuum discharge tube in which an object is placed opposite the cathode, or negative electrode.
		Some years before J.J. Thomson’s landmark discovery of the electron in 1897, Crookes used a fluorescence tube to demonstrate that some particle of matter was traveling from the cathode to the target object, causing it to fluoresce.
		In this mineral fluorescence tube, handmade in the United States by an American scientific glassblower, a piece of calcium tungstate, the same mineral used in x-ray fluoroscopic screens, is handsomely bezeled inside the bell of the tube.
	people.clarityconnect.com /webpages2/arcsandsparks/mineraltube.html (233 words)

	Cathode ray tube Summary
		The earliest version of the CRT was a cold-cathode diode, a modification of the Crookes tube with a phosphor-coated screen, sometimes called a Braun tube.
		The tube for oscilloscope use is longer and narrower, reducing the deflection angle (presumably for greater accuracy/linearity?), and deflection is done by applying an electrical field via deflection plates built into the tube's neck.
		Indirectly-heated vacuum tubes (including CRTs) use Barium compounds and other reactive materials in the cionstuction of the cathode and getter assemblies, normaly this material will be converted into oxides upon exposure to the air, but care should be taken to avoid contact with the inside of all broken tubes.
	www.bookrags.com /Cathode_ray_tube (4896 words)

	Eine Neue Art von Strahlen / On a New Kind of Rays W.C. RÖNTGEN (Roentgen) 28dec1895
		Using a very soft tube one obtains dark pictures in which the bones are not very prominent; when a harder tube is used, the bones become clearly visible in all details, while the soft parts are weak in comparison, and with a very hard tube one obtains only weak shadows, even of the bones.
		If we take a tube that has not yet been used nor even evacuated and connect it to the mercury pump, we shall reach after the necessary pumping and heating of the tube a degree of evacuation in which the _first x-rays may be noticed by a feeble light on a nearby fluorescent screen.
		With such a tube that had become very hard I obtained a very beautiful photographic shadow picture of the double barrel of a hunting gun with cartridges in place, in which all details of the cartridges, the internal faults of the damask barrels, and so forth, could be recognized very distinctly and sharply.
	www.mindfully.org /Nucs/Roetgen-X-Rays28dec1895.htm (8795 words)

	UM Physics Demonstration
		Crookes' tube is a device for producing a wide beam of high speed electrons, originally made by the British scientist Sir William Crookes in the late 1800's.
		The tube is fired by connecting it to the large induction coil.
		Crookes' tubes were very popular in Victorian times as a decoration at fancy gatherings.
	www.physics.lsa.umich.edu /demolab/demo.asp?id=344 (175 words)

	Crookes, Sir William - HighBeam Encyclopedia (Site not responding. Last check: 2007-11-03)
		Crookes, Sir William 1832-1919, English chemist and physicist.
		Crookes devised spectacles to protect the eyes of glassworkers from damaging rays.
		One of his chief inventions is the Crookes tube, with which J. Thomson, W. Roentgen, R. Millikan, and others conducted important research.
	www.encyclopedia.com /doc/1E1-crookes.html (303 words)

	Crookes Tube (Site not responding. Last check: 2007-11-03)
		Crookes (1832 - 1919) built a simple apparatus in about 1875 to study the effect of gas pressure on the voltage necessary to cause a spark.
		Crookes was able to examine the voltage necessary to get a spark (which could easily be detected by the use of an ampmeter in the system).
		If there was a small amount of residual gas in the tube, electrons moving from the cathode to the anode would strike gas molecules creating positively charged ions.
	neon.chem.uidaho.edu /~honors/crookes.html (519 words)

	Cathode Rays & the Discovery of the Electron
		His studies of electrical discharges in gases, which followed the development of the cathode ray tube by Pluecker and Hittorf, and his observations of cathode rays and the dark space at the cathode led to the discovery of x-rays and of the electron.
		Curiously, Crookes was a believer in the occult and in the 1870’s claimed to have verified the authenticity of psychic phenomena.
		In 1897 Crookes was knighted by Queen Victoria (who is also reputed to have had an interest in the occult) and in 1909 was elected president of the Royal Society.
	www.ee.umd.edu /~taylor/Electrons1.htm (812 words)

	TVAVE.com -- Cathode Ray Tube
		In a cathode ray tube, the electrons are carefully directed into a beam, and this beam is deflected by a magnetic or electric field to scan the surface at the viewing end (anode), which is lined with phosphorescent material (usually based on transition metals or rare earths).
		In case of a television and modern computer monitors, the entire front area of the tube is scanned in a fixed pattern called a raster, and a picture is created by modulating the intensity of the electron beam according to the programme's video signal.
		The tube for this kind of use is longer and narrower, and deflection is done by applying an electrical field via deflection plates built into the tube's neck.
	www.tvave.com /cathoderaytube.html (829 words)

	Cathode Ray Tube (CRT) - Early Experimentation, Vacuum Tubes, Crookes' Tube
		When most of the air was evacuated from the tube, an electrical charge could be seen jumping across the gap between the two electrodes.
		So great an improvement over Geissler's tubes were these that the "Crookes tube" quickly became the standard vacuum tube for use in scientific experiments.
		Crookes continued Plucker's experiments with magnetic fields, confirming the glow was easily deflected.
	www.discoveriesinmedicine.com /Bar-Cod/Cathode-Ray-Tube-CRT.html (1010 words)

	Vacuum tubes
		Six tubes, with different pressures inside, are mounted on the same panel placed vertically on an wooden basis.
		The tubes are held a the bottom by a metallic strip with a binding post placed on the basis, at the top they are held by single metallic plates anchored to the panel.
		The tube can serve to determinate the speed of the cathode rays and the ration between an electron charge and its mass.
	spazioinwind.libero.it /gabinetto_di_fisica/tubi/vacuumtubesu.htm (470 words)

	X-ray
		An early improvement in the X-ray tube was the introduction of a curved cathode to focus the beam of electrons on a heavy-metal target, called the anticathode, or anode.
		It is essentially a thermionic vacuum tube in which the cathode emits electrons because the cathode is heated by an auxiliary current and not because it is struck by ions as in the earlier types of tubes.
		The widely used shockproof tube is a modification of the Coolidge tube with improved insulation of the envelope (by oil) and grounded power cables.
	library.thinkquest.org /C001429/waves/x_ray_page_2_of_4.htm (689 words)

	Early Crookes Tube (Known as well as Hittorf Tube) (Site not responding. Last check: 2007-11-03)
		The glass extension and the stopper on the underside of the tube, allow the introduction of different gases inside the tube, as well as the control of the vacuum.
		The variations in the visible cathode beam between the electrodes were studied according to the voltages applied, according to the degree of vacuum, and according to the nature of the residual gas.
		Both the cathode and the anode are flat discs of aluminium since this is the only metal which does not appreciably disintegrate under the influence of the electric discharge.
	home.comcast.net /~znhakim/2_early_crookes.htm (204 words)

	Maltese Cross Crookes Tube (Site not responding. Last check: 2007-11-03)
		This type of tube was invented in the 1880s by William Crookes during his investigations unto the nature of cathode rays (electrons).
		The tube's most distinctive feature is the Maltese Cross that could be laid flat or stood up so that the cathode ray beam impinged upon it.
		It might have been that Crookes used a Maltese Cross because the pronunciation of his name is not that different from the pronunciation of the Latin word for cross: crux.
	www.orau.org /ptp/collection/xraytubes/maltesecross.htm (159 words)

	Crookes Tube With Three Anodes
		When a high voltage is applied, the cathode rays leaving the cupped cathode form three beams - one beam going to each anode.
		The beams are visible due to the fluorescence of the gas molecules caused by the electrons traveling through the tube.
		The age of this tube is uncertain, possibly late 1800s or early 1900s.
	www.orau.org /ptp/collection/xraytubes/threeanodes.htm (56 words)

	Geissler tube - Wikipedia, the free encyclopedia
		The Geissler tube is a glass tube for demonstrating the principles of electrical discharge.
		The tube was invented by the German glassblower Heinrich Geissler in 1857.
		William Crookes developed a modification of the Geissler tube into what is known as the Crookes tube to demonstrate and study these rays, later determined to be a stream of electrons.
	en.wikipedia.org /wiki/Geissler_tube (443 words)

	Crookes Tube (Site not responding. Last check: 2007-11-03)
		The Crookes tube was named after the British chemist and physicist Sir William Crookes (1832-1919).
		The Crookes tube is the predecessor of the cathode ray tube that made television possible though its primary use is as a classroom demonstration device.
		The interior of the tube is evacuated, and when a sufficiently high voltage is applied, a stream of electrons travel from the cathode (the small end) toward the anode (at the center bottom of the tube).
	uv201.com /Misc_Pages/crookes_tube.htm (172 words)

	Pear shaped Crookes Tube (Site not responding. Last check: 2007-11-03)
		Instead of having the electrodes “in line” on the opposite sides of the tube, as in the early Crookes tube, the cathode is a flat aluminium plate on the narrow side of the “pear” while the anode is “rod shaped” in a tubular lateral extension on the larger side.
		These rays, of an unknown nature yet, were produced by a large area of the glass wall on the larger side of the tube, by the impact of the unfocused “cathode rays” (electron beam).
		Such tubes were soon abandoned for the production of X-rays, and replaced by what came to be known as “the focus tube”.
	home.comcast.net /~znhakim/3_pear_shaped_crookes.htm (145 words)

	Glass
		In 1878, Crookes became convinced that the dark space he has observed between the cathode and the glow, extended farther from the cathode as the pressure inside the glass tube was reduced.
		This tube is used to demonstrate the effect of vacuum on radiant matter.
		In the second tube, the radiant matter travels in straight lines from the cathode, causing fluorescence of the walls of the tube directly opposite.
	www.sparkmuseum.com /GLASS.HTM (919 words)

	Crookes Tube - Search Results - MSN Encarta
		Invented by the British chemist and physicist Sir William Crookes, the...
		Cathode rays, or beams of electrons in evacuated glass tubes, were first noted by the British chemist and physicist Sir William Crookes in 1878.
		Crookes, Sir William (1832-1919), British chemist and physicist, born in London, and educated at the Royal College of Chemistry.
	encarta.msn.com /Crookes_Tube.html (118 words)

	Geissler and Crookes Tubes
		These tubes were probably made by (or for) Heinrich Geissler, possibly as early as 1850.
		While the top (on the right working) tube of this pair is one of the best electrical "gizmos" I have ever seen, it is also a demonstration of the glass blowers art.
		The lower tube is a dual chamber tube filled with Neon on the left and Mercury vapor on the right.
	www.oneillselectronicmuseum.com /page9.html (391 words)

	Xray invention (Site not responding. Last check: 2007-11-03)
		During his work, Crooke found that the tube gave off a strange glow and his photographic plates were continually ruined.
		A minor improvement was to focus the beam of electrons; previously the x-rays depended on the gas pressure within the Crookes tube.
		The Coolidge tube is still used today in a modern day form; shockproof tube with improved insulation of the envelope and grounded power cables.
	www.personal.psu.edu /users/t/j/tjf191/Invention.html (740 words)

	ISS: Biography of William Crookes
		Crookes' experiments with Daniel D. Home demonstrated the existence of a 'psychic force' wholly ignored by science.
		Crookes' article in the Quarterly Journal of Science, and their judicial tone, present a striking contrast to the inaccuracy, spiteful depreciation, under the shield of anonymity, of other men's work and the grotesque self-assertion which disfigured Dr. Carpenter's criticism".
		Crookes began by establishing whether Cook and King were two separate entities; this he proved beyond all reasonable doubt.
	www.survivalafterdeath.org /researchers/crookes.htm (517 words)

Try your search on: Qwika (all wikis)