| 单词 | galvanometer |
| 例句 | “As the galvanometer spot swung across the scale, indicating that protons of 1-MeV energy were reaching the collector,” Livingston recalled, “Lawrence literally danced around the room with glee.” Big Science 2015-07-07T00:00:00Z Helmholtz’s use of the galvanometer symbolized not just how scientists were measuring human capacity, but why. A Deadly Wandering: A Mystery, a Landmark Investigation, and the Astonishing Science of Attention in the Digital Age 2014-09-23T00:00:00Z He used an electric current to stimulate an amphibian’s calf, then employed the galvanometer to measure how long it took the electrical current to run along the sciatic nerve. A Deadly Wandering: A Mystery, a Landmark Investigation, and the Astonishing Science of Attention in the Digital Age 2014-09-23T00:00:00Z When a galvanometer detected a signal, it created a magnetic field. A Deadly Wandering: A Mystery, a Landmark Investigation, and the Astonishing Science of Attention in the Digital Age 2014-09-23T00:00:00Z The heart of most analog meters is a device called a galvanometer, denoted by G. Current flow through a galvanometer, IG , produces a proportional needle deflection. College Physics for AP Courses 2015-08-12T00:00:00Z He used a galvanometer with a tube that he could fill with various gases. Scientists understood the climate 150 years ago better than the EPA head today | John Abraham 2017-03-31T04:00:00Z Two scientists, Lucien Bull and Charles Nordmann, adapted the string galvanometer, which was used to measure small electrical currents, to record signals from the microphones on to photographic film. Amazing Photo Shows the Moment the Guns Fell Silent It was, therefore, the earliest example of a true “magnetic” telegraph, all preceding experiments to 300 this end having been on the galvanometer or needle principle. Encyclopaedia Britannica, 11th Edition, Volume 13, Slice 3 "Helmont, Jean" to "Hernosand" 2012-04-14T02:00:23.707Z This application was271 anticipated by Thomson, and is distinctly mentioned in his recorder patent, long before such galvanometers were ever used. Lord Kelvin An account of his scientific life and work 2012-04-06T02:00:32.097Z The two crucial characteristics of a given galvanometer are its resistance and current sensitivity. College Physics for AP Courses 2015-08-12T00:00:00Z But, in fact, it is easy to show that there is no electricity produced; for, when a galvanometer was interposed in the chain, no deviation of the needle took place. Mysterious Psychic Forces An Account of the Author's Investigations in Psychical Research, Together with Those of Other European Savants 2012-03-28T02:00:29.747Z On rebounding, the ball was arrested whilst the excursion of the galvanometer needle was observed. Modern Machine-Shop Practice, Volumes I and II 2012-03-23T02:00:33.140Z Fortunately, the means of ascertaining these data can be all combined in one instrument, known as a linesman's galvanometer or detector, of which we give an illustration at Fig. Electric Bells and All About Them A Practical Book for Practical Men 2012-03-06T03:00:25.273Z The mirror galvanometer then invented has become one of the most useful instruments of the laboratory. Lord Kelvin An account of his scientific life and work 2012-04-06T02:00:32.097Z By connecting resistors to this galvanometer in different ways, you can use it as either a voltmeter or ammeter that can measure a broad range of voltages or currents. College Physics for AP Courses 2015-08-12T00:00:00Z One of these he connected with a galvanometer, the other could be connected at will with a battery. Heroes of Science: Physicists 2012-01-17T03:00:17Z The electromotive force thus generated is measured by a galvanometer, the scale of which is divided and figured so that the temperature may be directly read. Encyclopaedia Britannica, 11th Edition, Volume 12, Slice 1 "Gichtel, Johann" to "Glory" 2012-01-11T03:00:20.463Z He exhibited a tube containing copper filings loosely held between two copper plugs and joined in series with a galvanometer and cell. Hertzian Wave Wireless Telegraphy 2012-01-09T03:00:20.570Z The galvanometer was replaced later by another invention of Professor Thomson—the siphon recorder. Lord Kelvin An account of his scientific life and work 2012-04-06T02:00:32.097Z That choice involves switching an appropriate resistance into series with the galvanometer. College Physics for AP Courses 2015-08-12T00:00:00Z On sending the battery current through the latter coil, the galvanometer needle swung completely round four or five times, and a similar action took place, but in the opposite direction, on stopping the current. Heroes of Science: Physicists 2012-01-17T03:00:17Z The third wire is for the indication of the contacts, and is taken from all the instruments to the galvanometer in the home station.—Industries. Scientific American Supplement, No. 648, June 2, 1888. 2011-12-26T03:00:15.410Z Secondly, the magnetising current is stopped, and soon after that the secondary coil is unshort-circuited and connected to the galvanometer, and remains in this condition during the remainder of the revolution. Hertzian Wave Wireless Telegraphy 2012-01-09T03:00:20.570Z Its inertia, or resistance to being set into motion, was thus very small, and it was hung by a single fibre of silk within a closed chamber at the centre of the galvanometer coil. Lord Kelvin An account of his scientific life and work 2012-04-06T02:00:32.097Z Figure 21.32 A large resistance R placed in series with a galvanometer G produces a voltmeter, the full-scale deflection of which depends on the choice of R . College Physics for AP Courses 2015-08-12T00:00:00Z As soon as the iron core touched the magnets, a current appeared in the galvanometer. Heroes of Science: Physicists 2012-01-17T03:00:17Z The current is passed through the platinum wires, and its strength measured by means of a galvanometer interposed in the circuit. Hawkins Electrical Guide, Number One Questions, Answers, & Illustrations, A Progressive Course of Study for Engineers, Electricians, Students and Those Desiring to acquire a Working Knowledge of Electricity and its Applications 2011-12-24T03:07:54.823Z The demagnetisation of the iron which ensues produces an electromotive force in the secondary coil and causes a deflection of the galvanometer, and this deflection will continue and remain steady if the oscillation persists. Hertzian Wave Wireless Telegraphy 2012-01-09T03:00:20.570Z The arrangement of magnet and suspended coil in this instrument has become widely known as that of the "d'Arsonval galvanometer." Lord Kelvin An account of his scientific life and work 2012-04-06T02:00:32.097Z Since the shunt resistance is small, most of the current passes through it, allowing an ammeter to measure currents much greater than those producing a full-scale deflection of the galvanometer. College Physics for AP Courses 2015-08-12T00:00:00Z The galvanometer connected with the coil showed a transient current. Heroes of Science: Physicists 2012-01-17T03:00:17Z One of these helices was connected with a galvanometer, and the other with a battery of one hundred pairs of plates, four inches square, with double coppers, and well charged. Hawkins Electrical Guide, Number One Questions, Answers, & Illustrations, A Progressive Course of Study for Engineers, Electricians, Students and Those Desiring to acquire a Working Knowledge of Electricity and its Applications 2011-12-24T03:07:54.823Z An exceedingly small silver ring is suspended by a quartz fibre and has a mirror attached to it in the manner of a galvanometer. Hertzian Wave Wireless Telegraphy 2012-01-09T03:00:20.570Z The galvanometer was also enclosed in a thick iron case to guard it against the magnetic field due to the iron of the ship. Lord Kelvin An account of his scientific life and work 2012-04-06T02:00:32.097Z One solution to the problem of voltmeters and ammeters interfering with the circuits being measured is to use galvanometers with greater sensitivity. College Physics for AP Courses 2015-08-12T00:00:00Z A current flowed through the galvanometer as long as the disc was kept spinning. Heroes of Science: Physicists 2012-01-17T03:00:17Z When the contact was made there was a sudden and very slight effect at the galvanometer, and there was also a similar slight effect when the contact with the battery was broken.” Hawkins Electrical Guide, Number One Questions, Answers, & Illustrations, A Progressive Course of Study for Engineers, Electricians, Students and Those Desiring to acquire a Working Knowledge of Electricity and its Applications 2011-12-24T03:07:54.823Z Besides devising numerous useful forms of galvanometers and other electrical instruments of precision, Werner Siemens was one of the discoverers of the principle of the self-acting dynamo. The Romance of Industry and Invention 2011-12-19T03:00:43.870Z This problem Thomson also solved by the invention of his mirror galvanometer. Lord Kelvin An account of his scientific life and work 2012-04-06T02:00:32.097Z Since no current flows through the galvanometer, none flows through the unknown emf, and so emfx is directly sensed. College Physics for AP Courses 2015-08-12T00:00:00Z The current from the frictional machine also served to deflect the needle of his galvanometer. Heroes of Science: Physicists 2012-01-17T03:00:17Z So far it seems to differ very little from the ordinary galvanometer previously mentioned, but the stroke of genius was in the method of reading it. Marvels of Scientific Invention An Interesting Account in Non-technical Language of the Invention of Guns, Torpedoes, Submarine Mines, Up-to-date Smelting, Freezing, Colour Photography, and many other recent Discoveries of Science 2011-11-19T03:00:24.517Z The very elaborate and delicate electrocardiograph with the string galvanometer devised by Einthoven is used. Arteriosclerosis and Hypertension: with Chapters on Blood Pressure, 3rd Edition. 2011-10-11T02:01:07.890Z The current from the whirling disk flowed through the galvanometer. The Story of Great Inventions 2011-10-05T02:00:16.353Z In both cases, no current passes through the galvanometer, and so the current I through the long wire is the same. College Physics for AP Courses 2015-08-12T00:00:00Z In making these measurements Cavendish was his own galvanometer. Heroes of Science: Physicists 2012-01-17T03:00:17Z The task of watching the rocking to and fro of the spot of light was found to be too nerve-racking for the telegraph operators, and so Lord Kelvin improved upon his galvanometer in two ways. Marvels of Scientific Invention An Interesting Account in Non-technical Language of the Invention of Guns, Torpedoes, Submarine Mines, Up-to-date Smelting, Freezing, Colour Photography, and many other recent Discoveries of Science 2011-11-19T03:00:24.517Z The electrician is watching a spot of light on the scale of an instrument which is called a galvanometer. Scientific Culture, and Other Essays Second Edition; with Additions 2011-09-17T02:00:31.747Z The current flowed calmly through the battery wire without producing, during its flow, any effect upon the galvanometer. The Story of Great Inventions 2011-10-05T02:00:16.353Z Because a long uniform wire is used for R , the ratio of resistances Rx / Rs is the same as the ratio of the lengths of wire that zero the galvanometer for each emf. College Physics for AP Courses 2015-08-12T00:00:00Z The quality of a galvanometer in this respect is best estimated by taking the logarithmic decrement of the oscillations when the movable system is set swinging. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 4 "G" to "Gaskell, Elizabeth" 2011-08-24T02:00:20.690Z So now we have two types of galvanometer, both due originally to the inventions of Lord Kelvin. Marvels of Scientific Invention An Interesting Account in Non-technical Language of the Invention of Guns, Torpedoes, Submarine Mines, Up-to-date Smelting, Freezing, Colour Photography, and many other recent Discoveries of Science 2011-11-19T03:00:24.517Z The spot of light, which the electrician is watching, is reflected from one of the latest of these inventions, the reflecting galvanometer of Thomson. Scientific Culture, and Other Essays Second Edition; with Additions 2011-09-17T02:00:31.747Z One coil was connected with a galvanometer, the other with a battery of ten cells, yet not the slightest turning of the needle could be observed. The Story of Great Inventions 2011-10-05T02:00:16.353Z Furthermore, it is not possible to tell when the galvanometer reads exactly zero, which introduces error into both Rx and Rs , and may also affect the current I . College Physics for AP Courses 2015-08-12T00:00:00Z This form of mirror galvanometer was first devised in connexion with submarine cable signalling, but soon became an indispensable instrument in the physical laboratory. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 4 "G" to "Gaskell, Elizabeth" 2011-08-24T02:00:20.690Z Once again we must turn our thoughts back to the string galvanometer. Marvels of Scientific Invention An Interesting Account in Non-technical Language of the Invention of Guns, Torpedoes, Submarine Mines, Up-to-date Smelting, Freezing, Colour Photography, and many other recent Discoveries of Science 2011-11-19T03:00:24.517Z The irregular movements given the galvanometer needle by the varying current are clearly delineated on the paper. Inventions in the Century 2011-07-20T02:00:14.643Z The coil and the needle together are called a galvanometer, and may be used to tell when a current is flowing, and also to indicate the strength of the current. The Story of Great Inventions 2011-10-05T02:00:16.353Z With no current running through the galvanometer, it has no effect on the rest of the circuit. College Physics for AP Courses 2015-08-12T00:00:00Z In its simple and original form the movable needle galvanometer consisted of a horizontal magnetic needle suspended within a coil of insulated wire by silk fibres or pivoted on a point like a compass needle. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 4 "G" to "Gaskell, Elizabeth" 2011-08-24T02:00:20.690Z This inertia, it is easy to see, militates against the accurate recording of rapid variations in minute currents, so the energetic Professor set about devising a new galvanometer which should answer his purpose. Marvels of Scientific Invention An Interesting Account in Non-technical Language of the Invention of Guns, Torpedoes, Submarine Mines, Up-to-date Smelting, Freezing, Colour Photography, and many other recent Discoveries of Science 2011-11-19T03:00:24.517Z The finer and more delicately poised a mechanism—whether it be chemical balance, galvanometer, electroscope or what not—the more sensitive is it to its surroundings. Household Administration Its Place in the Higher Education of Women 2011-07-20T02:00:13.547Z The instrument on the left in a glass case is his galvanometer. The Story of Great Inventions 2011-10-05T02:00:16.353Z This equation is used to calculate the unknown resistance when current through the galvanometer is zero. College Physics for AP Courses 2015-08-12T00:00:00Z The direction of such a needle is controlled Movable needle galvanometer. by the direction of the terrestrial magnetic force within the coil. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 4 "G" to "Gaskell, Elizabeth" 2011-08-24T02:00:20.690Z The galvanometer, it will be remembered, measures minute currents; the electrometer measures minute pressures, particularly those of small electrically charged bodies. Marvels of Scientific Invention An Interesting Account in Non-technical Language of the Invention of Guns, Torpedoes, Submarine Mines, Up-to-date Smelting, Freezing, Colour Photography, and many other recent Discoveries of Science 2011-11-19T03:00:24.517Z Repeated trials with a delicate galvanometer, applied to measure electric tension in the air, have proved these facts, which are now found useful for aiding, with the barometer and thermometer, in forecasting weather. A Treatise on Meteorological Instruments Explanatory of Their Scientific Principles, Method of Construction, and Practical Utility 2011-06-19T02:00:15.717Z Very fine metal filings were enclosed in a tube of ebonite and connected in a circuit with a battery and a galvanometer. The Story of Great Inventions 2011-10-05T02:00:16.353Z Both can be based on the combination of a resistor and a galvanometer, a device that gives an analog reading of current. College Physics for AP Courses 2015-08-12T00:00:00Z In the other type, or movable coil galvanometer, the coil is suspended and the magnet fixed; hence the coil tends to set itself with its axis parallel to the lines of force of the magnet. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 4 "G" to "Gaskell, Elizabeth" 2011-08-24T02:00:20.690Z The other principal kind of electrometer we owe, as we do the galvanometers, to the wonderful ingenuity of Lord Kelvin. Marvels of Scientific Invention An Interesting Account in Non-technical Language of the Invention of Guns, Torpedoes, Submarine Mines, Up-to-date Smelting, Freezing, Colour Photography, and many other recent Discoveries of Science 2011-11-19T03:00:24.517Z Since the current is the same through both, the resistances will be proportional to the galvanometer deflections, and from the known value of the standard resistance the value of the unknown resistance can be calculated. The New Gresham Encyclopedia Volume 4, Part 2: Ebert to Estremadura 2011-04-14T02:00:56.200Z These arms Relative determinations. are then altered until on raising or depressing the battery key there is no sudden deflection either way of the galvanometer. Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 3 "Electrostatics" to "Engis" 2011-02-06T03:00:53.093Z To produce a galvanometer for use in analog voltmeters and ammeters that have a low resistance and respond to small currents, we use a large loop area A , high magnetic field B , and low-resistance coils. College Physics for AP Courses 2015-08-12T00:00:00Z In some cases two wires are wound on in parallel, constituting a “differential galvanometer.” Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 4 "G" to "Gaskell, Elizabeth" 2011-08-24T02:00:20.690Z A little mirror is attached to the needle, so that its slightest motion is revealed by the movement of a spot of light, as in the case of the mirror galvanometers. Marvels of Scientific Invention An Interesting Account in Non-technical Language of the Invention of Guns, Torpedoes, Submarine Mines, Up-to-date Smelting, Freezing, Colour Photography, and many other recent Discoveries of Science 2011-11-19T03:00:24.517Z Provided the resistance of the galvanometer and other parts of the circuit is negligible in comparison with the resistance to be measured, the resistances are inversely as the deflections. The New Gresham Encyclopedia Volume 4, Part 2: Ebert to Estremadura 2011-04-14T02:00:56.200Z If a condenser of capacity C is charged to potential V, and discharged n times per second through a galvanometer, this series of intermittent discharges is equivalent to a current nCV. Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 3 "Electrostatics" to "Engis" 2011-02-06T03:00:53.093Z The galvanometer is used to detect any current induced in the coil on the bottom. College Physics for AP Courses 2015-08-12T00:00:00Z If the current to be measured is too large to be passed entirely through the galvanometer, a portion is allowed to flow through a circuit connecting the two terminals of the instrument. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 4 "G" to "Gaskell, Elizabeth" 2011-08-24T02:00:20.690Z It may occur to readers to inquire why the oscillating currents are not passed direct to a galvanometer. Marvels of Scientific Invention An Interesting Account in Non-technical Language of the Invention of Guns, Torpedoes, Submarine Mines, Up-to-date Smelting, Freezing, Colour Photography, and many other recent Discoveries of Science 2011-11-19T03:00:24.517Z The mechanical force produced when a current flows in a conductor placed in a magnetic field forms the basis of the action of electric motors, and certain types of galvanometers and measuring instruments. The New Gresham Encyclopedia Volume 4, Part 2: Ebert to Estremadura 2011-04-14T02:00:56.200Z If a galvanometer is in the circuit, the increased deflection of the instrument will indicate the presence of the waves. Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 2 "Ehud" to "Electroscope" 2011-01-29T03:00:23.777Z It was found that each time the switch is closed, the galvanometer detects a current in one direction in the coil on the bottom. College Physics for AP Courses 2015-08-12T00:00:00Z By the sensitiveness of the 430 galvanometer is meant the deflexion produced by a known electromotive force put upon its terminals or a known current sent through it. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 4 "G" to "Gaskell, Elizabeth" 2011-08-24T02:00:20.690Z Professor Korn uses a form of the Einthoven galvanometer already described. Marvels of Scientific Invention An Interesting Account in Non-technical Language of the Invention of Guns, Torpedoes, Submarine Mines, Up-to-date Smelting, Freezing, Colour Photography, and many other recent Discoveries of Science 2011-11-19T03:00:24.517Z A galvanometer is connected in series with a standard high resistance and a steady source of E.M.F. The New Gresham Encyclopedia Volume 4, Part 2: Ebert to Estremadura 2011-04-14T02:00:56.200Z The solution of the well-known problem of finding the current in the galvanometer circuit of the arrangement of linear conductors called Wheatstone’s Bridge is thus easily obtained. Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 2 "Ehud" to "Electroscope" 2011-01-29T03:00:23.777Z Interestingly, if the switch remains closed or open for any length of time, there is no current through the galvanometer. College Physics for AP Courses 2015-08-12T00:00:00Z If the latter condition is fulfilled the galvanometer is said to be “dead-beat.” Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 4 "G" to "Gaskell, Elizabeth" 2011-08-24T02:00:20.690Z This, at the remote end, operates the Einthoven galvanometer, the movements of which vary the shade of the spiral line being drawn upon the photographic paper. Marvels of Scientific Invention An Interesting Account in Non-technical Language of the Invention of Guns, Torpedoes, Submarine Mines, Up-to-date Smelting, Freezing, Colour Photography, and many other recent Discoveries of Science 2011-11-19T03:00:24.517Z In this way a photographic record of the movements of the galvanometer mirror is obtained. The New Gresham Encyclopedia Volume 4, Part 2: Ebert to Estremadura 2011-04-14T02:00:56.200Z Thus the deflection of the galvanometer can be used to indicate the arrival of electric waves. Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 2 "Ehud" to "Electroscope" 2011-01-29T03:00:23.777Z When the switch is opened and closed, the galvanometer registers currents in opposite directions. College Physics for AP Courses 2015-08-12T00:00:00Z This last term is defined as the logarithm of the ratio of one swing to the next succeeding swing, and a galvanometer of which the logarithmic decrement is large, is said to be highly damped. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 4 "G" to "Gaskell, Elizabeth" 2011-08-24T02:00:20.690Z Thus the flowing and stopping of the oscillating currents is exactly copied by the current from the battery, which current is led through a telephone or a sensitive galvanometer. Marvels of Scientific Invention An Interesting Account in Non-technical Language of the Invention of Guns, Torpedoes, Submarine Mines, Up-to-date Smelting, Freezing, Colour Photography, and many other recent Discoveries of Science 2011-11-19T03:00:24.517Z The effect of this is to increase the deflection on the ship's insulation galvanometer, thus serving as a continuity test. The Story of the Atlantic Telegraph 2010-12-29T03:00:29.577Z Lord Kelvin’s mirror galvanometer was first used in receiving signals through the short-lived 1858 cable. Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 2 "Ehud" to "Electroscope" 2011-01-29T03:00:23.777Z How does the magnitude of the force depend on the resistance of the galvanometer? College Physics for AP Courses 2015-08-12T00:00:00Z The Einthoven string galvanometer is another form of sensitive instrument for the measurement of small direct currents. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 4 "G" to "Gaskell, Elizabeth" 2011-08-24T02:00:20.690Z Another product of the oxyhydrogen flame is the quartz fibres which are used for suspending the needles in the finest galvanometers. Marvels of Scientific Invention An Interesting Account in Non-technical Language of the Invention of Guns, Torpedoes, Submarine Mines, Up-to-date Smelting, Freezing, Colour Photography, and many other recent Discoveries of Science 2011-11-19T03:00:24.517Z But the galvanometer of Professor Thomson, that instrument of marvellous delicacy, drew faint whispers from its muttering lips. The Story of the Atlantic Telegraph 2010-12-29T03:00:29.577Z Instruments called galvanometers and ammeters for the most part operate on this principle. Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 2 "Ehud" to "Electroscope" 2011-01-29T03:00:23.777Z Current sensitivity is the current that gives a full-scale deflection of the galvanometer’s needle, the maximum current that the instrument can measure. College Physics for AP Courses 2015-08-12T00:00:00Z Alternating Current Galvanometers.—For the detection of small alternating currents a magnetic needle or movable coil galvanometer is of no utility. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 4 "G" to "Gaskell, Elizabeth" 2011-08-24T02:00:20.690Z The answer is that because they are oscillating a very sensitive galvanometer is not possible. Marvels of Scientific Invention An Interesting Account in Non-technical Language of the Invention of Guns, Torpedoes, Submarine Mines, Up-to-date Smelting, Freezing, Colour Photography, and many other recent Discoveries of Science 2011-11-19T03:00:24.517Z The following are the three candidates whose names are variously associated with the “invention” of the first constructed electromagnetic instrument, or “multiplier,” or primitive galvanometer. The Earliest Electromagnetic Instruments Polarization and Contact Difference of Potential.—If we connect together in series a single Daniell’s cell, a galvanometer, and two platinum electrodes dipping into acidulated water, no visible chemical decomposition ensues. Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 2 "Ehud" to "Electroscope" 2011-01-29T03:00:23.777Z Suppose you want 10 V to produce a full- scale deflection of a voltmeter containing a 25-Ω galvanometer with a 50-µA sensitivity. College Physics for AP Courses 2015-08-12T00:00:00Z In course of time both the original form of single needle galvanometer and mirror galvanometer were improved by introducing the astatic principle and weakening the external controlling magnetic field. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 4 "G" to "Gaskell, Elizabeth" 2011-08-24T02:00:20.690Z Two thousand miles away, the galvanometer felt and was operated by the force generated in a battery about the size of one of the capital letters on this page. Marvels of Scientific Invention An Interesting Account in Non-technical Language of the Invention of Guns, Torpedoes, Submarine Mines, Up-to-date Smelting, Freezing, Colour Photography, and many other recent Discoveries of Science 2011-11-19T03:00:24.517Z It is called a “galvanometer,” consistent with Ampère’s definition of that word. The Earliest Electromagnetic Instruments Now let us disconnect the platinum plates from the battery and join them directly with the galvanometer. Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 2 "Ehud" to "Electroscope" 2011-01-29T03:00:23.777Z For other voltage ranges, other resistances are placed in series with the galvanometer. College Physics for AP Courses 2015-08-12T00:00:00Z The earth’s magnetic field can be weakened by means of a controlling magnet arranged to create in the space in the interior of the galvanometer coils an extremely feeble controlling magnetic field. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 4 "G" to "Gaskell, Elizabeth" 2011-08-24T02:00:20.690Z The galvanometer has a near relative, the electrometer, the astounding delicacy of which renders it equally interesting. Marvels of Scientific Invention An Interesting Account in Non-technical Language of the Invention of Guns, Torpedoes, Submarine Mines, Up-to-date Smelting, Freezing, Colour Photography, and many other recent Discoveries of Science 2011-11-19T03:00:24.517Z The manner in which the string galvanometer is arranged to reproduce a transmitted picture is shown in Fig. Wireless Transmission of Photographs Second Edition, Revised and Enlarged 1919 Various instruments called permeameters and hysteresis meters have been designed for this purpose, but much of the work has been done by means of a ballistic galvanometer and test ring as above described. Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 2 "Ehud" to "Electroscope" 2011-01-29T03:00:23.777Z Figure 21.33 A small shunt resistance R placed in parallel with a galvanometer G produces an ammeter, the full-scale deflection of which depends on the choice of R . College Physics for AP Courses 2015-08-12T00:00:00Z In this Movable coil galvanometer. instrument a permanent magnet, generally of the horseshoe shape, is employed to create a strong magnetic field, in which a light movable coil is suspended. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 4 "G" to "Gaskell, Elizabeth" 2011-08-24T02:00:20.690Z Light rays are reflected from the suspended particles to the sensitive plate of a photoelectric cell; this generates a current of electricity which causes a deflection on a galvanometer. Myology and Serology of the Avian Family Fringillidae A Taxonomic Study The Einthoven galvanometer consists of a very powerful electro-magnet, the pole pieces of which converge almost to points. Wireless Transmission of Photographs Second Edition, Revised and Enlarged 1919 At first a considerable current is indicated by the galvanometer; the deflexion soon diminishes, however, and finally becomes very small. Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 2 "Ehud" to "Electroscope" 2011-01-29T03:00:23.777Z The various scales are achieved by switching various shunt resistances in parallel with the galvanometer—the greater the maximum current to be measured, the smaller the shunt resistance must be. College Physics for AP Courses 2015-08-12T00:00:00Z In the practical construction of the suspended needle fixed coil galvanometer great care must be taken with the insulation of the wire of the coil. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 4 "G" to "Gaskell, Elizabeth" 2011-08-24T02:00:20.690Z There is one person who sits gripping the carbon electric handle connected with this galvanometer who, to begin with, had a resistance of over sixty thousand. The Social Gangster A De' Arsonval galvanometer H is also connected to the switch X, so that either the telephone or the galvanometer can be switched in. Wireless Transmission of Photographs Second Edition, Revised and Enlarged 1919 The wires leading from the coherers to the galvanometer are also surrounded by metal tubes to protect them from stray radiation. Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 2 "Ehud" to "Electroscope" 2011-01-29T03:00:23.777Z This allows construction of voltmeters with greater resistance and ammeters with smaller resistance than when less sensitive galvanometers are used. College Physics for AP Courses 2015-08-12T00:00:00Z In the construction of a movable coil galvanometer, it is usual to intensify the magnetic field by inserting a fixed soft iron core in the interior of the movable coil. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 4 "G" to "Gaskell, Elizabeth" 2011-08-24T02:00:20.690Z Kennedy was the calmest one of us all as he tapped the little galvanometer significantly with his index finger. The Social Gangster Let G be a galvanometer connected with the wires from a helix; N S, a permanent bar magnet. The Telephone An Account of the Phenomena of Electricity, Magnetism, and Sound, as Involved in Its Action He seems in this way to have educated in himself a very precise “electrical sense,” making use of his own nervous system as a kind of physiological galvanometer. Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 2 "Ehud" to "Electroscope" 2011-01-29T03:00:23.777Z There are practical limits to galvanometer sensitivity, but it is possible to get analog meters that make measurements accurate to a few percent. College Physics for AP Courses 2015-08-12T00:00:00Z A galvanometer can be calibrated, or the meaning of its deflexion determined, by passing through it an electric current of known value and observing the deflexion of the needle or coil. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 4 "G" to "Gaskell, Elizabeth" 2011-08-24T02:00:20.690Z In this condition there is complete electrical insulation between the jets, as may be proved by the inclusion in the circuit of a delicate galvanometer, and a low electromotive force. Encyclopaedia Britannica, 11th Edition, Volume 5, Slice 3 "Capefigue" to "Carneades" The current of electricity in the opposite direction is indicated by the galvanometer needle, which moves according to Ampère's law mentioned on a preceding page. The Telephone An Account of the Phenomena of Electricity, Magnetism, and Sound, as Involved in Its Action Weber effected great improvements in them and in the construction and use of galvanometers. Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 2 "Ehud" to "Electroscope" 2011-01-29T03:00:23.777Z The segment of wire has a resistance Rx and script Ex = IRx , where I is unaffected by the connection since no current flows through the galvanometer. College Physics for AP Courses 2015-08-12T00:00:00Z This metal disk galvanometer has been made sufficiently sensitive to detect the feeble oscillatory electric currents set up in the receiving wire of a wireless telegraph apparatus. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 4 "G" to "Gaskell, Elizabeth" 2011-08-24T02:00:20.690Z From a galvanic battery and a galvanometer on the ground two insulated copper wires were to extend to the balloon, one connected to the mercury and the other to the clock frame. The Introduction of Self-Registering Meteorological Instruments This developed magnetism will re-act upon a coil of wire, and so move a galvanometer needle. The Telephone An Account of the Phenomena of Electricity, Magnetism, and Sound, as Involved in Its Action It led at once to the construction of the galvanometer as a means of detecting and measuring the electric current in a conductor. Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 2 "Ehud" to "Electroscope" 2011-01-29T03:00:23.777Z The device is called a bridge because the galvanometer forms a bridge between two branches. College Physics for AP Courses 2015-08-12T00:00:00Z In a form of astatic needle galvanometer devised by Professor A. Broca of Paris, the pair of magnetized needles are suspended vertically and parallel to each other with poles in opposite directions. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 4 "G" to "Gaskell, Elizabeth" 2011-08-24T02:00:20.690Z The deflection of the galvanometer was to be timed with a second clock on the ground. The Introduction of Self-Registering Meteorological Instruments If the magnet be thrust into the coil, a current of electricity will traverse the helix, wire, and galvanometer, and the needle will indicate its direction. The Telephone An Account of the Phenomena of Electricity, Magnetism, and Sound, as Involved in Its Action One of these coils was connected with the voltaic battery and the other with the galvanometer. Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 2 "Ehud" to "Electroscope" 2011-01-29T03:00:23.777Z The variable resistance R3 is adjusted until the galvanometer reads zero with the switch closed. College Physics for AP Courses 2015-08-12T00:00:00Z The Duddell thermal ammeter is another very sensitive form of alternating current galvanometer. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 4 "G" to "Gaskell, Elizabeth" 2011-08-24T02:00:20.690Z This current, which can be easily measured by putting a galvanometer in series with the discharging point, is independent of z, the vertical distance of a plane between A and B below the charging point. Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 8 "Conduction, Electric" Thus originated the galvanometer, an instrument that not only detects the existence of an electric current, but enables us to determine its direction and its strength. The Telephone An Account of the Phenomena of Electricity, Magnetism, and Sound, as Involved in Its Action He found that at the moment the current in the battery circuit was started or stopped, transitory currents appeared in the galvanometer circuit in opposite directions. Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 2 "Ehud" to "Electroscope" 2011-01-29T03:00:23.777Z First, it is not possible to get the current through the galvanometer to be exactly zero. College Physics for AP Courses 2015-08-12T00:00:00Z The time marks were made by two galvanometer Henry. needles, when successive screens were broken by a shot. Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 3 "Chitral" to "Cincinnati" With alternating currents, however, it is impossible to use a galvanometer in the usual way. Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 8 "Conduction, Electric" He had me touch an insulated wire to the frost-covered stone from space, while he put the other end to one post of a galvanometer. Astounding Stories, March, 1931 The tube must be tapped between each experiment, and the deflection of the galvanometer brought back to about its original value. Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 2 "Ehud" to "Electroscope" 2011-01-29T03:00:23.777Z Each time the switch is opened, the galvanometer detects a current in the opposite direction. College Physics for AP Courses 2015-08-12T00:00:00Z “This large, squat telescope catches and concentrates on the thermocouple and the galvanometer registers the temperature.” Astounding Stories of Super-Science, March 1930 The galvanometer was therefore replaced by Kohlrausch by a telephone, which gives a sound when an alternating current passes through it. Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 8 "Conduction, Electric" How can one who is ignorant of the existence and characteristics of rotational inertia understand a galvanometer? College Teaching Studies in Methods of Teaching in the College The sensitiveness of the coherer depends on the electromotive force put in the galvanometer circuit. Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 2 "Ehud" to "Electroscope" 2011-01-29T03:00:23.777Z No current flows through the galvanometer when the switch remains closed or open. College Physics for AP Courses 2015-08-12T00:00:00Z The galvanometer consists of a magnet set up inside coils through which the current I spoke of flows. Astounding Stories of Super-Science, March 1930 Thus any residual current through the galvanometer is direct and not alternating. Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 8 "Conduction, Electric" A galvanometer actuated by a thermo-electric pile furnishes much the most sensitive means of detecting changes of temperature; hence electricity enables the physicist to study the phenomena of heat with new ease and precision. Little Masterpieces of Science: Invention and Discovery The magnetic field still remains about the little magnets, otherwise this combination would be of no value in the construction of galvanometers. How Two Boys Made Their Own Electrical Apparatus Containing Complete Directions for Making All Kinds of Simple Apparatus for the Study of Elementary Electricity Diagram of galvanometer coil, used with recording apparatus for resistance thermometers in water-circuit 40 21. Respiration Calorimeters for Studying the Respiratory Exchange and Energy Transformations of Man If you will manipulate the telescope so as to search the hills around here, I will watch the galvanometer.” Astounding Stories of Super-Science, March 1930 The high moment of inertia of the coil makes the period of swing slow compared with the period of alternation of the current, and the slight periodic disturbances are thus prevented from affecting the galvanometer. Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 8 "Conduction, Electric" “When the plate was in the magnetic meridian, or in any other plane coinciding with the magnetic dip, then its rotation produced no effect upon the galvanometer.” Little Masterpieces of Science: Invention and Discovery A perspective view of this apparatus is shown in the tangent galvanometer. How Two Boys Made Their Own Electrical Apparatus Containing Complete Directions for Making All Kinds of Simple Apparatus for the Study of Elementary Electricity Directly in front of the table the galvanometer is suspended from the ceiling and a black hood extends from the observer's table to the galvanometer itself. Respiration Calorimeters for Studying the Respiratory Exchange and Energy Transformations of Man “Merely a thermocouple attached to a D’Arsonval galvanometer,” replied the doctor. Astounding Stories of Super-Science, March 1930 Exhibits of original galvanometers and other apparatus will trace the development of cardiography. History of the Division of Medical Sciences United States National Museum Bulletin 240, Contributions from the Museum of History and Technology, paper 43, 1964 Rotates a galvanometer needle by an electric pulse. Little Masterpieces of Science: Invention and Discovery Imagine that we have a galvanometer connected with Y and Z. If the battery current enters at W, it will pass along A to 4, before it can find a chance to escape. How Two Boys Made Their Own Electrical Apparatus Containing Complete Directions for Making All Kinds of Simple Apparatus for the Study of Elementary Electricity The two galvanometer coils, fl and fr, are wound differentially and both coils most carefully balanced so that the two windings have equal temperature coefficients. Respiration Calorimeters for Studying the Respiratory Exchange and Energy Transformations of Man When they are at different temperatures, an electrical potential is set up, which causes a current to flow from one to the other through the galvanometer. Astounding Stories of Super-Science, March 1930 A galvanometer was readily affected by using the saddle conductors, applied to the anterior and posterior parts of the gymnotus. The World's Greatest Books — Volume 15 — Science It is true that the scientific instruments of the laboratory, such as the galvanometer, do not record thought vibrations. Genuine Mediumship or The Invisible Powers When the strength of a current is to be measured, or the strengths of two currents are to be compared, the apparatus is called a galvanometer. How Two Boys Made Their Own Electrical Apparatus Containing Complete Directions for Making All Kinds of Simple Apparatus for the Study of Elementary Electricity The galvanometer is of the Deprez-d'Arsonval type and is extremely sensitive. Respiration Calorimeters for Studying the Respiratory Exchange and Energy Transformations of Man A quantity so large was cut off, that the needle of the galvanometer, promptly quitting the zero line, moved with energy to its stops. Fragments of science, V. 1-2 The deflection was constantly in a given direction, the electric current being always from the anterior part of the animal through the galvanometer wire to the posterior parts. The World's Greatest Books — Volume 15 — Science The galvanometer spoke again in its peculiar harsh voice. The Ultimate Weapon The strength of different currents can be compared, and many interesting experiments performed with the tangent galvanometer. How Two Boys Made Their Own Electrical Apparatus Containing Complete Directions for Making All Kinds of Simple Apparatus for the Study of Elementary Electricity This is indicated at the top of the diagram near the galvanometer. Respiration Calorimeters for Studying the Respiratory Exchange and Energy Transformations of Man The two faces of the pile were in the first instance brought to the same temperature; the equilibrium being shown by the needle of the galvanometer standing at zero. Fragments of science, V. 1-2 This conclusion is in perfect accordance with the degree of deflection which the discharge can produce in a galvanometer needle, and also with the amount of chemical decomposition produced in the electrolysing experiments. The World's Greatest Books — Volume 15 — Science The galvanometer needle showed what slight variations in the current there were during the course of the treatment. The Problems of Psychical Research Experiments and Theories in the Realm of the Supernormal For full explanations, and for the study of experimental cells, etc., by means of the tangent galvanometer, see text-book. How Two Boys Made Their Own Electrical Apparatus Containing Complete Directions for Making All Kinds of Simple Apparatus for the Study of Elementary Electricity The galvanometer is suspended from the ceiling of the calorimeter laboratory and is free from vibration. Respiration Calorimeters for Studying the Respiratory Exchange and Energy Transformations of Man Behind the screen, but so situated that no ray from the ball could reach the instrument, was an excellent Thermo-electric pile, connected by wires with a very delicate galvanometer. Fragments of science, V. 1-2 The coil carrier can now be adjusted to the galvanometer frame by means of screws at D, which pass through wide holes in the carrier and bold the latter in position by their heads. On Laboratory Arts Will it affect the galvanometer needle, or other delicate electrical or physical instruments? The Problems of Psychical Research Experiments and Theories in the Realm of the Supernormal An instrument for measuring static electricity, differing from a galvanometer, which measures a current in a wire that acts on the magnetic needle p. 197of the galvanometer. Electricity for Boys On the top shelf is seen the galvanometer and on the lower shelf the recorder with its glass door in front and the coordinate paper dropping into the box below. Respiration Calorimeters for Studying the Respiratory Exchange and Energy Transformations of Man But on permitting the gas to rise from the ball, it casts an amount of heat against the adjacent face of the pile sufficient to impel the needle of the galvanometer almost to 90°. Fragments of science, V. 1-2 In the sectional plan the parts of the galvanometer frame are shown shaded. On Laboratory Arts Again, we have a purely experimental method of studying the emotions—by means of the galvanometer. The Problems of Psychical Research Experiments and Theories in the Realm of the Supernormal An instrument, like a galvanometer, which determines whether or not a current is present in a tested wire. Electricity for Boys So long as both galvanometer coils are influenced by exactly the same strength of current, the pointer will stand in line with and immediately below i and no current passes through the recording apparatus. Respiration Calorimeters for Studying the Respiratory Exchange and Energy Transformations of Man The quantity absorbed by the oxygen under those circumstances was too feeble to affect the galvanometer; the gas, in fact, proved perfectly transparent to the rays of heat. Fragments of science, V. 1-2 C C C are slotted brackets adjustable to the pins and capable of rotation by releasing the screws E E. D D are the screws holding the coil carriage to the galvanometer framework. On Laboratory Arts Thus the deflection of the galvanometer was made to indicate the arrival of electric waves. Sir Jagadis Chunder Bose His Life and Speeches An instrument, like a galvanometer, that shows the direction in which a current is flowing through a p. 193conductor. Electricity for Boys The maximum sensitiveness of the galvanometer is retained when the connection is made with the Wheatstone bridges. Respiration Calorimeters for Studying the Respiratory Exchange and Energy Transformations of Man Falling upon a thermo-electric pile, its invisible presence is shown by the prompt deflection of even a coarse galvanometer. Fragments of science, V. 1-2 Threads for galvanometer suspensions are conveniently from 0.0001 to 0.0004 inch in diameter, and are much more easily made and got uniform than thicker threads, to the production of which the catapult method applies. On Laboratory Arts The nerve circuit may be liked to an electric circuit, and invisible impulse bringing about response in the indicator, be it the brain or the galvanometer. Sir Jagadis Chunder Bose His Life and Speeches Thomson greatly simplified the galvanometer, and Wheatstone invented the rheostat, a means of measuring resistance, about 1850. Electricity for Boys Above the chair calorimeter can be seen the balance for weighing the subject, and at its right the galvanometer suspended from the ceiling. Respiration Calorimeters for Studying the Respiratory Exchange and Energy Transformations of Man It was then found that an instant's exposure of the face of the thermoelectric pile to the focus of invisible rays, dashed the needles of a coarse galvanometer violently aside. Fragments of science, V. 1-2 The tests on which these statements are based were continued for about two years, during which time kerosene and mineral oils had no observable effect on shellac-fastened galvanometer mirrors. On Laboratory Arts Well, on that table stands Professor Thomson’s delicate and wonderful galvanometer. The Battery and the Boiler Adventures in Laying of Submarine Electric Cables When the apparatus is in operation, the coherer switch is closed, and the instant a current passes through the coherer and operates the telegraph sounder, the galvanometer indicates the current. Electricity for Boys The galvanometer is of the Deprez-d'Arsonval type and has a particularly powerful magnetic field, in which a double coil swings suspended similar to the marine galvanometer coils. Respiration Calorimeters for Studying the Respiratory Exchange and Energy Transformations of Man No one dares address him, or ask the questions all are longing to have answered, and when his lips move silently we know that he is muttering over galvanometer readings to himself. A Woman's Journey through the Philippines On a Cable Ship that Linked Together the Strange Lands Seen En Route For the future it will be better always to make galvanometer mirrors from quartz crystals. On Laboratory Arts “Yes, sir, I remember it well,” responded Robin,—“the room into which the conducting-wires from the ends of the cable are led to the testing-tables, on which are the curious-looking galvanometers and other testing machines.” The Battery and the Boiler Adventures in Laying of Submarine Electric Cables An instrument which reveals this condition is called a galvanometer. Electricity for Boys In front of this galvanometer coil and inclosed in the same air-tight metal case is the plunger contact Pl, fig. Respiration Calorimeters for Studying the Respiratory Exchange and Energy Transformations of Man In the testing room, that Holy of Holies on board a cable-ship, the fate of the Burnside hangs upon a tiny, quivering spark of light thrown upon the scale by the galvanometer’s mirror. A Woman's Journey through the Philippines On a Cable Ship that Linked Together the Strange Lands Seen En Route To get good mirrors for galvanometers, I have found the best plan is to grind and polish a large number together, on a disc perhaps 8 or 10 inches in diameter. On Laboratory Arts Suddenly, at 3:15 a.m., when exactly eighty-four miles of cable had been laid out, he who observed the galvanometer saw the speck of light glide to the end of the scale, and vanish! The Battery and the Boiler Adventures in Laying of Submarine Electric Cables Instantly a point of red light, surrounded by a vivid orange circle, appeared upon the screen, low down and to the left of center, and the timing galvanometer showed a wide positive deflection. Spacehounds of IPC On the top shelf is the galvanometer, and immediately beneath, the plug resistance box for altering the value of certain shunts. Respiration Calorimeters for Studying the Respiratory Exchange and Energy Transformations of Man Posthypnotic suggestion, crystal-gazing, automatic writing and trance-speech, the willing-game, etc., are now, thanks to him, instruments of research, reagents like litmus paper or the galvanometer, for revealing what would otherwise be hidden. Memories and Studies Quartz fibres have two great advantages over other forms of suspension when employed for any kind of torsion balance, from an ordinary more or less "astatic" galvanometer to the Cavendish apparatus. On Laboratory Arts A galvanometer in the thermo-couple circuit indicates when the Page 213 balance point is reached, since at this point the galvanometer needle will stand motionless when its circuit is opened and closed. The Working of Steel Annealing, Heat Treating and Hardening of Carbon and Alloy Steel His mirror galvanometer was the first instrument that could be applied with anything like satisfactory results to submarine telegraphy. Western Worthies A Gallery of Biographical and Critical Sketches of West of Scotland Celebrities The cup may now be filled with water, and connection made with a galvanometer by non-polarisable electrodes. Response in the Living and Non-Living The current from the line, L, flows at the receiving station through a powerful galvanometer, G, to earth. Scientific American, Volume 40, No. 13, March 29, 1879 A Weekly Journal of Practical Information, Art, Science, Mechanics, Chemistry, and Manufactures The current used should be from 20 to 80 milliampères, gradually increasing from zero, without shock; three to six large Bunsen cells give a sufficient current, and no galvanometer is required. Manual of Surgery Volume First: General Surgery. Sixth Edition. At this time the galvanometer is thrown in series with SC. The Working of Steel Annealing, Heat Treating and Hardening of Carbon and Alloy Steel For some time after the cable was laid he remained at Valentia, endeavouring to bring his galvanometer to still greater perfection. Western Worthies A Gallery of Biographical and Critical Sketches of West of Scotland Celebrities E E′ non-polarising electrodes connecting A and B with galvanometer G. Stimulus produces ‘negative variation’ of current of rest. Response in the Living and Non-Living The galvanometer has a stout needle, one tip of which is connected to a duplicate pen, P, by a thread, t, which is kept taut by a second thread stretched by a spring, s'. Scientific American, Volume 40, No. 13, March 29, 1879 A Weekly Journal of Practical Information, Art, Science, Mechanics, Chemistry, and Manufactures Now I have in a hole in the wall an instrument no bigger than a galvanometer, of which a model is on the table. Scientific American Supplement, No. 717, September 28, 1889 At this time the galvanometer will indicate a balance in the same way as when it was used with a thermo-couple. The Working of Steel Annealing, Heat Treating and Hardening of Carbon and Alloy Steel I suspected this was going to happen, but I tested the battery with a galvanometer to-day and I found out it has about ten flashes left. The Moving Picture Boys on the War Front Or, The Hunt for the Stolen Army Films But if we interpose the galvanometer in the electrolytic part of the circuit, that is to say, at W, the same current will appear to flow in the opposite direction. Response in the Living and Non-Living The current from the line, L', flows through a similar galvanometer, G', to earth. Scientific American, Volume 40, No. 13, March 29, 1879 A Weekly Journal of Practical Information, Art, Science, Mechanics, Chemistry, and Manufactures We do know that fresh fruits and vegetables are strongly magnetic because the magnetism which they emit can be gauged by means of delicate galvanometers. The Healthy Life, Vol. V, Nos. 24-28 The Independent Health Magazine In respect of many inconveniences which are connected with the use of an electrometer, I have tried the measurements with a very sensitive galvanometer. Scientific American Supplement, No. 633, February 18, 1888 The unbroken lines represent the curves obtained with the apparatus just described, while the dotted ones give the curve of deflection of an ordinary tangent galvanometer. Scientific American Supplement, No. 508, September 26, 1885 The current in the galvanometer through the non-polarisable electrode is from left to right. Response in the Living and Non-Living Now, since the needle of each of these galvanometers deflects in proportion to the strength of the current flowing through its coil, the points of these two needles keep moving with the varying currents. Scientific American, Volume 40, No. 13, March 29, 1879 A Weekly Journal of Practical Information, Art, Science, Mechanics, Chemistry, and Manufactures With an instrument of this kind and a very delicate galvanometer, Professor Henry found that the heat from a person's face could be perceived at a distance of several hundred feet. Scientific American Supplement, No. 443, June 28, 1884 When the lower end of the kite line was communicating with the galvanometer whose other terminal was in contact with the earth, a current passed through the galvanometer. Scientific American Supplement, No. 633, February 18, 1888 These curves show that for strong intensities of current Mr. Kapp's instrument is more advantageous than the tangent galvanometer. Scientific American Supplement, No. 508, September 26, 1885 These two faces may be put in connection with a galvanometer by means of two non-polarisable electrodes, whose ends dip into the two chambers. Response in the Living and Non-Living In the ice is a thermoelectric junction, the wires leading to which are in communication with a reflecting galvanometer. The Birth-Time of the World and Other Scientific Essays If, now, one set of the junctures is heated more than the other set, a current of electricity will be generated, which will affect the galvanometer. Scientific American Supplement, No. 443, June 28, 1884 During the motion of the coil, a strong deflection of the galvanometer is observed; but the deflection ceases as soon as the coil ceases to rotate. General Science The increase is sufficient to make itself easily seen by the motion of a galvanometer. The Story of the Living Machine A Review of the Conclusions of Modern Biology in Regard to the Mechanism Which Controls the Phenomena of Living Activity The galvanometer spot is thrown down on the drum by the inclined mirror M. The galvanometer deflection takes place at right angles to the motion of the paper. Response in the Living and Non-Living In the second and third columns are shown, respectively, the coefficient and angle of friction, whilst the fourth gives the temperature of the ice as determined from the galvanometer deflexions. The Birth-Time of the World and Other Scientific Essays The sensitiveness of the latter may be regulated by a magnetic system like that of the galvanometer. Scientific American Supplement, No. 421, January 26, 1884 Current-measuring instruments, or galvanometers, depend for their action on the magnetic properties of current electricity. General Science The motion of the galvanometer under these conditions gives a ready means of studying the character of the nervous impulse. The Story of the Living Machine A Review of the Conclusions of Modern Biology in Regard to the Mechanism Which Controls the Phenomena of Living Activity The resistance of the electrolyte in the cell is thus relatively small, and the galvanometer deflections are proportional to the E.M. variations. Response in the Living and Non-Living The needle of the galvanometer remains in equilibrium if the two currents yield equal quantities of electricity during one and the same time, τ. Scientific American Supplement, No. 613, October 1, 1887 Finally, there is a lateral scale, R, which carries a magnetized bar, A, that may be slid toward the galvanometer. Scientific American Supplement, No. 421, January 26, 1884 A galvanometer does not measure the current, but merely indicates the relative strength of different currents. General Science Upon giving the armature an angular motion limited by two stops, there develops a certain quantity of electricity that may be measured by causing it to traverse an appropriate ballistic galvanometer. Scientific American Supplement, No. 441, June 14, 1884. If the galvanometer deflection is ‘up’ when A alone is excited, the excitation of B will give rise to a downward deflection. Response in the Living and Non-Living A battery of an arbitrary electromotive force, E, actuates at the same time the two antagonistic circuits of a differential galvanometer. Scientific American Supplement, No. 613, October 1, 1887 Among the galvanometers, we remarked an apparatus that was exhibited by Prof. Zenger, of Prague. Scientific American Supplement, No. 421, January 26, 1884 Instruments for measuring the strength of currents in units are called ammeters, and the common form makes use of a galvanometer. General Science Measuring apparatus were represented by a new and very elegant arrangement of Sir William Thomson's reflecting galvanometers, due to Mr. J. Carpentier. Scientific American Supplement, No. 441, June 14, 1884. By disturbing the balance of the potentiometer, the galvanometer deflection due to a known increase of E.M.F. was found from which the absolute E.M. variation caused by disturbance of copper or zinc was determined. Response in the Living and Non-Living The heat sets up an electric current in the joined metals, and this current is read on a galvanometer graduated to read degrees Fahrenheit instead of volts, so that the temperature may be read direct. How To Write Special Feature Articles A Handbook for Reporters, Correspondents and Free-Lance Writers Who Desire to Contribute to Popular Magazines and Magazine Sections of Newspapers By placing the galvanometer in the circuit of the battery, as shown in Fig. Scientific American Supplement, No. 794, March 21, 1891 The black cord still traveled through the wheels unbroken, and the test applied by the galvanometer proved the insulation to be perfect. St. Nicholas, Vol. 5, No. 5, March, 1878 Mr R. Anderson's apparatus is also very handy, consisting of a case containing three Leclanché cells, and a galvanometer with a "tangent" scale and certain standard resistances. Nitro-Explosives: A Practical Treatise This was balanced by a potentiometer arrangement, so that the galvanometer spot came to zero. Response in the Living and Non-Living A fluid amalgam of potassium, containing not more than a hundredth of that metal, was put into pure water, and connected, through the galvanometer with a plate of platina in the same water. Experimental Researches in Electricity, Volume 1 The deflection of the galvanometer needle will be very slight, showing that the resistance of clean water is considerable. Scientific American Supplement, No. 794, March 21, 1891 But Master Hugh in the dream was embracing an enormous retort, while a convenient galvanometer registered his emotion and little tripods danced around him. Mr. Britling Sees It Through He observed the throw of the galvanometer when the circuit which contained the battery and the electromagnet was opened by a key which at the same moment connected the electromagnet wires to the galvanometer. Scientific American Supplement, No. 787, January 31, 1891 The wires are fixed at their upper ends to two electrodes —leading to the galvanometer—and kept moderately and uniformly stretched by spiral springs. Response in the Living and Non-Living By a little adjustment of the distances these induced currents were rendered exactly equal, and the galvanometer needle remained stationary notwithstanding their frequent production in the instrument. Experimental Researches in Electricity, Volume 1 A few drops of sulphuric acid or even vinegar will increase the conductivity of the water so as to produce a marked deflection of the galvanometer needle. Scientific American Supplement, No. 794, March 21, 1891 It is noticeable that the needle of a galvanometer, starting from the middle position, goes gradually over to one side, eventually indicating a considerable deflection. Scientific American Supplement, No. 455, September 20, 1884 The throw of the galvanometer was assumed to represent the extra current which flowed out. Scientific American Supplement, No. 787, January 31, 1891 Complete Abolition of Response by Strong KOH The two vertical lines are galvanometer deflections due to ·1 volt, before and after the application of reagent. Response in the Living and Non-Living Then, for the copper plate was substituted one of sulphur 0.9 of an inch thick; still the results were exactly the same, i.e. there was no action at the galvanometer. Experimental Researches in Electricity, Volume 1 Now, by placing in the circuit, in addition to the galvanometer, the remaining coil of the magnet, thus introducing considerable resistance, the current will be diminished, as shown by a smaller deflection of the needle. Scientific American Supplement, No. 794, March 21, 1891 If now a constant current of electricity is passed through the apparatus, as indicated by a galvanometer, the variations of the latter will show the effect produced upon the selenium. Scientific American Supplement, No. 484, April 11, 1885 Connect it up as described, and observe the throw given to the galvanometer. Scientific American Supplement, No. 787, January 31, 1891 The resultant effect in the galvanometer will be due to EA-EB when EA and EB are the electrical variations produced at A and B by the stimulus. Response in the Living and Non-Living The helices were connected together, and also with a galvanometer, so that these two currents should coincide in direction, and tend by their joint force to deflect the needle of the instrument. Experimental Researches in Electricity, Volume 1 All work should be frequently tested for continuity with telephones, magnetos, or small portable galvanometers. Scientific American Supplement, No. 821, September 26, 1891 Consequently, the cylinder must be withdrawn from the circuit to represent this effect; and the maximum deviation of the galvanometer is then to be observed, and marked 100. Scientific American Supplement, No. 484, April 11, 1885 The armature of the magnet is placed gently upon the poles, and time enough is allowed to elapse for the galvanometer needle to settle to zero. Scientific American Supplement, No. 787, January 31, 1891 By means of a potentiometer the galvanometer spot may be brought back to the original position. Response in the Living and Non-Living When the soft iron bar was taken out of the helix and inverted in various directions within four feet of the galvanometer, not the slightest effect upon it was produced. Experimental Researches in Electricity, Volume 1 The mirror galvanometer is now almost entirely superseded by the siphon recorder. Scientific American Supplement, No. 795, March 28, 1891 By dividing the range of the galvanometer thus obtained into 100 equal parts, the requisite actinometric scale will be established. Scientific American Supplement, No. 484, April 11, 1885 I place the exploring coil just over the pole, and slide on the armature; then close the galvanometer circuit. Scientific American Supplement, No. 787, January 31, 1891 In order to study these effects we must use, in practice, a highly sensitive galvanometer as the recorder of E.M. variations. Response in the Living and Non-Living When the plate was in the magnetic meridian, or in any other plane coinciding with the magnetic dip, then its rotation produced no effect upon the galvanometer. Experimental Researches in Electricity, Volume 1 Those for cables are of two kinds, the mirror galvanometer and the siphon recorder, both the product of Sir Wm. Scientific American Supplement, No. 795, March 28, 1891 Prof. Bose found that when he attached the galvanometer to bars of various metals they gave a similar response when struck or twisted. A Series of Lessons in Gnani Yoga I will roughly repeat the experiment before you: The spot of light on the screen is reflected from my galvanometer at the far end of the table. Scientific American Supplement, No. 787, January 31, 1891 A current—the current of injury—is found to flow in the nerve, from the injured to the uninjured, and in the galvanometer, through the electrolytic contacts from the uninjured to the injured. Response in the Living and Non-Living I constantly obtained deflections at the galvanometer, but they were very irregular, and were, in succession, referred to other causes than that sought for. Experimental Researches in Electricity, Volume 1 The latter alternative was chosen, and the mirror galvanometer was the result. Scientific American Supplement, No. 795, March 28, 1891 He used a galvanometer, a very delicate and accurate scientific instrument, in his experiments. A Series of Lessons in Gnani Yoga The ends of this coil were carried to a distant part of the laboratory, and connected to a sensitive ballistic galvanometer. Scientific American Supplement, No. 787, January 31, 1891 If now a galvanometer be interposed at O, the current will flow from B to A through the galvanometer, i.e. from right to left. Response in the Living and Non-Living Both wires were then twisted together like the strands of a rope, for eighteen or twenty inches; and the remaining parts being made to diverge, their extremities were connected with the wires of the galvanometer. Experimental Researches in Electricity, Volume 1 Place the galvanometer on a level table and turn it until the needle, pointing north and south, and swinging freely, lies exactly in the plane of the coil, as shown in the cut. The Boy Mechanic: Volume 1 700 Things for Boys to Do If the galvanometer be attached to a human nerve, and the end of the nerve be irritated, the needle will register. A Series of Lessons in Gnani Yoga Startling indeed it is to the scientist to be told that an artificial dream-world of the mathematician is more real than that he sees with his galvanometers, ultra-microscopes, and spectroscopes. Architecture and Democracy The movement of the galvanometer needle during excitation of the tissue thus indicates a molecular upset by the stimulus; and the gradual creeping back of the galvanometer deflection exhibits a molecular recovery. Response in the Living and Non-Living The iron wire was about two feet long, the continuation to the galvanometer being copper. Experimental Researches in Electricity, Volume 1 A Bradley tangent galvanometer is used, employing the coil of 160 ohms resistance. Scientific American Supplement, No. 492, June 6, 1885 Professor Thomson devised his mirror galvanometer to meet this difficulty. Masters of Space Morse, Thompson, Bell, Marconi, Carty His consciousness was like the quivering little spot of light which is thrown by the mirror of a galvanometer. The Country of the Blind, and Other Stories In that case, stimulus will cause greater electrical disturbance at the more responsive point, say A, and this will be shown by the galvanometer as a current of response. Response in the Living and Non-Living The indicating galvanometer, in all experiments made with this magnet, was about eight feet from it, not directly in front of the poles, but about 16� or 17� on one side. Experimental Researches in Electricity, Volume 1 G Resistance of the shunt of a galvanometer. s Battery and its internal resistance. Scientific American Supplement, No. 595, May 28, 1887 The professor pointed out that had the mirror galvanometer been used with a moderate current the cable could have been continued in successful operation. Masters of Space Morse, Thompson, Bell, Marconi, Carty The man, who had cowered with surprise at her touch and voice, but had waited even then to finish an observation of his galvanometer before turning, now turned and stared at her. The Irrational Knot Being the Second Novel of His Nonage The galvanometer spot will then return more or less gradually to its original position, and that part of the curve which is traced during the process constitutes the recovery. Response in the Living and Non-Living A piece of copper plate wrapped once round the iron cylinder like a socket, but with interposed paper to prevent contact, had its edges connected with the wires of the galvanometer. Experimental Researches in Electricity, Volume 1 The current is made to pass into the series of voltameters by means of a commutator, and its intensity is shown by a Deprez galvanometer. Scientific American Supplement, No. 415, December 15, 1883 Other plates were placed on the opposite side of the waterway and were connected by a wire with a sensitive galvanometer in series to act as a receiver. Masters of Space Morse, Thompson, Bell, Marconi, Carty There was a second table near the door, crowded with coils, batteries, a galvanometer, and other electrical apparatus. The Irrational Knot Being the Second Novel of His Nonage If, further, the rate of recovery be the same for both points, then the electric disturbances produced at A and B will continue to balance each other, and the galvanometer will show no current. Response in the Living and Non-Living But the instant the plate moved, the galvanometer was influenced, and by revolving the plate quickly the needle could be deflected 90� or more. Experimental Researches in Electricity, Volume 1 Reflecting upon the principle of Professor Schweigger's galvanometer, he constructed magnets in which great power could be developed by a very small galvanic element. Samuel F. B. Morse, His Letters and Journals In Two Volumes, Volume II Currents sent from the opposite side were recorded by the galvanometer and the possibility of communication through the water was established. Masters of Space Morse, Thompson, Bell, Marconi, Carty It is reported that on another trial the light from the star Arcturus, when focussed on the vulcanite, was capable of deflecting the needle of the galvanometer. Heroes of the Telegraph In order that a resultant effect may be exhibited in the galvanometer, matters have to be so arranged that the disturbance may reach one point, say A, and not B, and vice versa. Response in the Living and Non-Living Perhaps if the galvanometer had consisted of fewer turns of thick wire instead of many convolutions of thinner, more striking effects would have been produced. Experimental Researches in Electricity, Volume 1 "Bless my galvanometer, don't go too fast on the start," cautioned Mr. Damon, nervously. Tom Swift and His Electric Runabout, or, the Speediest Car on the Road His telephone receiver provided the wireless experimenters with an instrument of extreme sensitiveness by which they were able to detect currents which the mirror galvanometer could not receive. Masters of Space Morse, Thompson, Bell, Marconi, Carty To indicate the effect, he included a galvanometer in the circuit of the battery and the button. Heroes of the Telegraph The resistance of the galvanometer is equal to 1,000 ohms. Response in the Living and Non-Living This wire was then divided in the middle, and connected by two cups of mercury with a delicate galvanometer. Experimental Researches in Electricity, Volume 1 A device for continuously indicating on a galvanometer the depths of the ocean. Edison, His Life and Inventions In medical galvanometers the proportions are no longer the same, and the needle is always very near the directing helix. Scientific American Supplement, No. 497, July 11, 1885 The apparatus consisted of a telephone button placed between two discs of platinum and connected in circuit with the battery and a sensitive galvanometer. Heroes of the Telegraph Owing to inertia of the recording galvanometer, however, there is a lag produced in the records of E.M. changes. Response in the Living and Non-Living To obtain perfectly satisfactory results a new galvanometer was constructed, consisting of two independent coils, each containing eighteen feet of silked copper wire. Experimental Researches in Electricity, Volume 1 A few drops of water or perfume thrown on the floor of a room are sufficient to give a very decided indication on the galvanometer in circuit with the instrument. Edison, His Life and Inventions As well known, Mr. Desains has demonstrated that this occurs likewise in sinus or tangent galvanometers; but these have helices that are very large in proportion to the needle. Scientific American Supplement, No. 497, July 11, 1885 A mirror attached to the suspension magnified the movement of the needle, and indicated the signals after the manner of the Thomson mirror galvanometer. Heroes of the Telegraph If the sheet of metal have been properly annealed, there will now be no difference of potential between the two faces, and no current in the galvanometer. Response in the Living and Non-Living On making and breaking contact between the soft iron bar and the poles of the magnet, the galvanometer was strongly affected; on detaching the zinc it was still more strongly affected in the same direction. Experimental Researches in Electricity, Volume 1 Put a coil of wire over the end of rod X and passed the ends of spool through galvanometer without affecting it in any way. Edison, His Life and Inventions The only instrument which could be used successfully in signalling through the Atlantic Cable was one of peculiar construction, by Professor Thompson, called the marine galvanometer. The Atlantic Monthly, Volume 05, No. 29, March, 1860 The mirror galvanometer is at once beautifully simple and exquisitely scientific. Heroes of the Telegraph My desire is that all present should see these results, and with that view I will try when practicable to use a mirror reflecting galvanometer instead of a telephone. Scientific American Supplement, No. 417, December 29, 1883 One of these helices was connected with a galvanometer, and the other with a battery of one hundred pairs of plates four inches square, with double coppers, and well charged. Experimental Researches in Electricity, Volume 1 This latter and the metal plate are connected in an electric circuit which includes a battery and a sensitive galvanometer. Edison, His Life and Inventions Thus the simple contact of pieces of zinc and copper with the nerves generated current sufficient to excite the muscles—a current which would require a delicate galvanometer for its detection. Scientific American Supplement, No. 433, April 19, 1884 The principle of the siphon recorder is exactly the inverse of the mirror galvanometer. Heroes of the Telegraph If the speed of the reverser be further increased, the greater part of the induced current is received on the opposite terminal of the galvanometer, so that a negative result is obtained. Scientific American Supplement, No. 417, December 29, 1883 When, however, the quantity of interposed fluid was reduced to a drop, the galvanometer gave no indication. Experimental Researches in Electricity, Volume 1 When the galvanometer shows the desired deflection, the needle, T, will indicate upon the dial, in decimal fractions of an inch, the exact distance through which the strip has been moved. Edison, His Life and Inventions On account of the nature of the experiment a high resistance Thomson reflecting galvanometer was used, with the following results. Scientific American Supplement, No. 433, April 19, 1884 His delicate mirror galvanometer has also been the forerunner of a later circle of equally precise apparatus for the measurement of current or dynamic electricity. Heroes of the Telegraph I have already shown you how this can be done by means of either a galvanometer or a telephone in circuit with a spiral wire. Scientific American Supplement, No. 417, December 29, 1883 No making or breaking of the contact at B side, or in any part of the galvanometer circuit, produced any effect at the galvanometer. Experimental Researches in Electricity, Volume 1 Another special instrument is a "dead beat" galvanometer which differs from the ordinary form of galvanometer in having no coils or magnetic needle. Edison, His Life and Inventions In this way it is possible to obtain a more evenly divided scale than in the case when the deflection follows the law of tangents, as in an ordinary tangent galvanometer. Scientific American Supplement, No. 433, April 19, 1884 The mirror receiving instrument employed was the heavy prototype of the delicate reflecting galvanometer of Sir William Thomson. Heroes of the Telegraph But if this smaller spiral be placed at a different angle to the larger one, it is, as you observe by the deflection of the galvanometer, again affected. Scientific American Supplement, No. 417, December 29, 1883 When the iron was brought in contact with the poles the galvanometer was strongly affected. Experimental Researches in Electricity, Volume 1 The two plates and the carbon button form part of an electric circuit containing a battery and a galvanometer. Edison, His Life and Inventions Ducretet described a galvanometer with steel magnet, which is surrounded by an exciting coil. Scientific American Supplement, No. 433, April 19, 1884 Within three weeks he had made, partly at Heidelberg, and partly at Frankfort, his first galvanometer, or needle telegraph. Heroes of the Telegraph The iron will now be removed, but the spirals left in the same position as before, and by increasing the speed of the reversals you see a higher deflection is given on the galvanometer. Scientific American Supplement, No. 417, December 29, 1883 Copper wires, one sixteenth of an inch in thickness, attached, in the ordinary manner, by convolutions to the other ends of these conductors, passed away to the galvanometer. Experimental Researches in Electricity, Volume 1 The instrument is so sensitive that with a delicate galvanometer it will show the impingement of the heat from a person's hand thirty feet away. Edison, His Life and Inventions Here we have a galvanometer with permanent calibration. Scientific American Supplement, No. 433, April 19, 1884 To these gifts of theory, electrical and mechanical, Thomson added a practical boon in the shape of the reflecting galvanometer, or mirror instrument. Heroes of the Telegraph As the room-walls had pretty much a uniform temperature, the deflection of the galvanometer was but slight, when the tube-axis of the thermopile was directed anywhere outside of the hot-air current rising from the flame. Scientific American Supplement, No. 385, May 19, 1883 The galvanometer was roughly made, yet sufficiently delicate in its indications. Experimental Researches in Electricity, Volume 1 The current pressure was regulated by a galvanometer. Edison, His Life and Inventions In some respects he's like—merely like, I say—a telephone engineer's galvanometer, that shows when and where a current has been interrupted. The Road to Damascus The professor employs a helix connected with a battery, and surrounding a portion of the wire in circuit with the galvanometer. Scientific American Supplement, No. 384, May 12, 1883 Connections are made between these contacts, cc, the resistance box, the prongs, k and l, of the forks, gg, and the reflecting galvanometer, as shown in Fig. Scientific American Supplement, No. 430, March 29, 1884 On passing the upper part of the rectangle from east to west over the galvanometer, the marked pole of the needle went east, and the current of electricity was therefore the reverse of the former. Experimental Researches in Electricity, Volume 1 There was the Thomson reflecting mirror galvanometer and electrometer, while nearby were the standard cells by which the galvanometers were adjusted and standardized. Edison, His Life and Inventions He had already made and described very important improvements in the construction of galvanometers, and he graduated his tangent galvanometer to correspond with the system of electric measurement he had adopted. Scientific American Supplement, No. 363, December 16, 1882 The current in the helix magnetizes the circuit wire inclosed, and the galvanometer exhibits the presence of electricity. Scientific American Supplement, No. 384, May 12, 1883 The positions of cc are then varied until the galvanometer shows no deflection when the key, T, is depressed. Scientific American Supplement, No. 430, March 29, 1884 In these experiments it is not necessary to move the galvanometer or needle from its first position. Experimental Researches in Electricity, Volume 1 Edison was intolerant of sham and shoddy, and nothing would satisfy him that could not stand cross-examination by microscope, test-tube, and galvanometer. Edison, His Life and Inventions Mr. Joule's improvements in galvanometers have already been incidentally mentioned, and the construction by him of accurate thermometers has been referred to. Scientific American Supplement, No. 363, December 16, 1882 These impulses have been measured by delicate galvanometers and magnified millions of times by modern amplifying apparatus. Autobiography of a Yogi Several galvanometers in the Magnetic Basement were destroyed. Autobiography of Sir George Biddell Airy When the moving part of the wire was carried up or down parallel to the dip, no effect was produced on the galvanometer. Experimental Researches in Electricity, Volume 1 On suddenly thrusting one end of a straight cylindrical magnet into the axis of the helix, the deflection of the galvanometer needle showed the presence of an electric current in the helix. Beacon Lights of History, Volume 14 The New Era; A Supplementary Volume, by Recent Writers, as Set Forth in the Preface and Table of Contents It should never be forgotten that he first used small enough needles in tangent galvanometers to practically annul error from want of uniformity of the magnetic field. Scientific American Supplement, No. 363, December 16, 1882 Back of this screen," he went on, indicating it in the corner of the room, "I have placed what is known as the string galvanometer, invented, or, perhaps better, perfected by Dr. Einthoven, of Leyden. Guy Garrick Though some scientists would call this merely a sensitive form of galvanometer," he remarked, "it is, to me, more than that. The Treasure-Train One wire from the galvanometer dipped into the mercury of the jar, and the other into the drop contained in the hole at the upper extremity of the axis. Experimental Researches in Electricity, Volume 1 In another experiment he employs a simple hollow coil, or helix, of insulated wire whose ends are connected with a galvanometer. Beacon Lights of History, Volume 14 The New Era; A Supplementary Volume, by Recent Writers, as Set Forth in the Preface and Table of Contents Passing a big dividing board," he went on, "they are distributed and connected each in its place to the delicate tangent galvanometers and sensitive indicators you see in this room. The War Terror Garrick was still engrossed in the study of what the galvanometer was showing. Guy Garrick A galvanometer is so arranged that its action swings a mirror from side to side, reflecting a light. The Dream Doctor The current gathered by the conductor and conveyed to the galvanometer was of the same kind on both sides of the place of greatest intensity, but gradually diminished in force from that place. Experimental Researches in Electricity, Volume 1 The magnet being left in the helix, the galvanometer needle came to rest, thus showing the absence of current. Beacon Lights of History, Volume 14 The New Era; A Supplementary Volume, by Recent Writers, as Set Forth in the Preface and Table of Contents A sensitive pile is also a delicate detector of heat by virtue of the current set up, which can be measured with a galvanometer or current meter. The Story of Electricity Still Garrick did not move from his post at the galvanometer. Guy Garrick Close to the wall was a stereopticon which shot a beam of light through a tube to which I heard them refer as a galvanometer, about three feet distant. The Dream Doctor On revolving the magnet screw fashion, the galvanometer needle was deflected in the same direction as before, but far more powerfully. Experimental Researches in Electricity, Volume 1 When the bar magnet was suddenly withdrawn from the helix, the galvanometer needle was again deflected, but now in the opposite direction, showing that the direction of the current in the helix had been reversed. Beacon Lights of History, Volume 14 The New Era; A Supplementary Volume, by Recent Writers, as Set Forth in the Preface and Table of Contents Thus a sensitive galvanometer will show a weak current if a copper wire connected in circuit with it be warmed at one point. The Story of Electricity Close to the wall at the left was a stereopticon which, as nearly as I could make out, shot a beam of light through a tube to a galvanometer about three feet distant. Guy Garrick "That's a marvellous piece of apparatus," I remarked, standing over the connections with the string galvanometer, after all had gone. The Dream Doctor All the results obtained with the galvanometer are more or less of this nature, the galvanometer extremity being the fixed part. Experimental Researches in Electricity, Volume 1 At last he notices that there is a slight movement of the galvanometer needle at the moment of making and breaking the circuit. Beacon Lights of History, Volume 14 The New Era; A Supplementary Volume, by Recent Writers, as Set Forth in the Preface and Table of Contents If the coil be closed through a small galvanometer G the movements of the needle to one side or the other will indicate these temporary currents. The Story of Electricity Between the poles of the galvanometer was stretched a slender thread of fused quartz plated with silver. Guy Garrick From what little knowledge I have of electricity I should have said it was, in part at least, a galvanometer, one of those instruments which register the intensity of minute electric currents. The Dream Doctor On putting the pole of a magnet under the revolving disc, the galvanometer needle could be permanently deflected. Experimental Researches in Electricity, Volume 1 The galvanometer caused a beam of light to vary--to grow brighter or dimmer, according as the electrical current was stronger or weaker. Tom Swift and His Photo Telephone or the Picture That Saved a Fortune In other meters the current passes through a species of galvanometer called an ampere meter, and controls a clockwork counter. The Story of Electricity You see," remarked Garrick, now engrossed on the apparatus and forgetting the hammer evidence for the time, "the beam of light focussed on that fine thread in the galvanometer passes to this photographic plate. Guy Garrick At once the galvanometer will register a larger amount of electromagnetic energy. Nature Cure The longer the extent of the moving wire, and the greater the space through which it moves, the greater is the effect upon the galvanometer. Experimental Researches in Electricity, Volume 1 Now then, as the electrical needle, moving across the copper plate, made electrical contacts of different degrees of strength, it worked a delicate galvanometer on the receiving end. Tom Swift and His Photo Telephone or the Picture That Saved a Fortune This can be seen by connecting the plates through a galvanometer, and allowing a ray of light to fall upon them. The Story of Electricity Garrick had moved behind the screen that cut off our view of the galvanometer. Guy Garrick On this principle is made the galvanometer for measuring the intensity of a current. Side-Lights on Astronomy and Kindred Fields of Popular Science A plate of clean platina was put into each cell and connected with a delicate galvanometer, but no electric current could be observed. Experimental Researches in Electricity, Volume 1 One of these helices was connected with a galvanometer and the other with a battery of a hundred pairs of plates four inches square, with double coppers and well charged. A History of Science — Volume 3 A small galvanometer G shows the indications of the testing current. The Story of Electricity Its pole being connected with one end of a galvanometer wire, and its equator with the other end, electricity rushes round the galvanometer from the rotating magnet. Faraday as a Discoverer When one was turned round so that both were in the same direction, the effect at the galvanometer was very powerful. Experimental Researches in Electricity, Volume 1 They were carefully examined by a powerful current of electricity and a galvanometer, and found to have no communication with each other. Experimental Researches in Electricity, Volume 1 The magneto-electricity developed in the coils of the revolving electro-magnet was measured by an accurate galvanometer; and the temperature of the water was taken before and after each experiment by a very delicate thermometer. A History of Science — Volume 3 A brass sliding piece S puts the galvanometer needle in and out of action. The Story of Electricity If the needle be at all oblique, in the wrong direction, to the coils of the galvanometer when the shock passes, effects of this kind are sure to happen. Experimental Researches in Electricity, Volume 1 With a more delicate galvanometer, an excellent swing of the needle could be obtained by one discharge of the battery. Experimental Researches in Electricity, Volume 1 The current was evident, both by the continued deflection of the galvanometer, and the production of bubbles of oxygen and hydrogen at the electrodes in cell iv. Experimental Researches in Electricity, Volume 1 To prove this, he constructed a disk that revolved between the poles of an electro-magnet, connecting the axis and the edge of the disk with a galvanometer. A History of Science — Volume 3 The needle of the galvanometer is deflected by it, until the resistance in the box R is adjusted to balance that in the rod. The Story of Electricity The upper ends were well-connected with the galvanometer wires. Experimental Researches in Electricity, Volume 1 They were then charged by thirty turns of the machine, and discharged through the galvanometer, a thick wet string, about ten inches long, being included in the circuit. Experimental Researches in Electricity, Volume 1 The galvanometer which I had occasion to use was rough in its construction, having but one magnetic needle, and not at all delicate in its indications. Experimental Researches in Electricity, Volume 1 Copper wires, one-sixteenth of an inch in thickness, attached in the ordinary manner by convolutions to the other ends of these conductors, passed away to the galvanometer. A History of Science — Volume 3 When this is so, the galvanometer needle remains at rest. The Story of Electricity On reversing the motion of the plate, the needle at the galvanometer was deflected in the opposite direction, showing an opposite current. Experimental Researches in Electricity, Volume 1 Thus, if the end B were upwards, such a magnet introduced from above would make the marked end of the galvanometer needle pass west. Experimental Researches in Electricity, Volume 1 If, after an interval during which the circuit had not been complete, the wire 3 were placed upon the paper, there was evidence of a current, decomposition ensued, and the galvanometer was affected. Experimental Researches in Electricity, Volume 1 The moveable part of the wire was then arranged below the galvanometer, but so as to be carried across the dip. Experimental Researches in Electricity, Volume 1 The copper wire was then divided in the middle, and examined by a delicate galvanometer, but no evidence of an electrical current was obtained. Experimental Researches in Electricity, Volume 1 The galvanometer needle moved as in former cases, and the direction of motion was the same as that which would have resulted, if the copper only had revolved, and the magnet been fixed. Experimental Researches in Electricity, Volume 1 Upon rotating the magnet and its attached cylinder, abundance of electricity passed through the galvanometer, and in the same direction as if the cylinder had rotated only, the magnet being still. Experimental Researches in Electricity, Volume 1 On changing the direction of the current through the galvanometer, the direction of the deflection of the needle was also changed. Experimental Researches in Electricity, Volume 1 The most instructive set of results was obtained, however, when the galvanometer was introduced at x. Experimental Researches in Electricity, Volume 1 The current thus separated was examined by galvanometers and decomposing apparatus introduced into the course of this wire. Experimental Researches in Electricity, Volume 1 When this arrangement was passed in a similar manner between the poles of the magnet, not the slightest effect at the galvanometer could be perceived. Experimental Researches in Electricity, Volume 1 On reversing the galvanometer communications so as to pass the discharge through from B to A, the needle was equally well deflected, but in the opposite direction. Experimental Researches in Electricity, Volume 1 Hence it would appear that if the same absolute quantity of electricity pass through the galvanometer, whatever may be its intensity, the deflecting force upon the magnetic needle is the same. Experimental Researches in Electricity, Volume 1 Collectors were then applied at the opposite edges of the disc, and wires from them connected with the galvanometer. Experimental Researches in Electricity, Volume 1 There was a very ready decomposition of the solution of iodide of potassium at b, and when metallic contact was made there, very considerable deflection of the galvanometer needle at g. Experimental Researches in Electricity, Volume 1 Otherwise the arrangement was as before, and exceedingly sensible; for a very slight motion of the magnet between the helices produced an abundant vibration of the galvanometer needle. Experimental Researches in Electricity, Volume 1 One of these wires was connected with the galvanometer, and the other with a voltaic battery. Experimental Researches in Electricity, Volume 1 The battery of fifteen jars was then charged by sixty revolutions of the machine, and discharged, as before, through the galvanometer. Experimental Researches in Electricity, Volume 1 The helix B was connected by copper wires with a galvanometer three feet from the ring. Experimental Researches in Electricity, Volume 1 All care was taken to render these results independent of the earth's magnetism, or of the mutual magnetism of the magnet and galvanometer needles. Experimental Researches in Electricity, Volume 1 The first point to be determined was, whether the same absolute quantity of ordinary electricity, sent through a galvanometer, under different circumstances, would cause the same deflection of the needle. Experimental Researches in Electricity, Volume 1 Not the slightest deflection of the galvanometer needle occurred. Experimental Researches in Electricity, Volume 1 No electrical indications at the galvanometer were observed. Experimental Researches in Electricity, Volume 1 A piece of common salt previously fused and solidified being introduced into the circuit was sufficient almost entirely to destroy the action on the galvanometer. Experimental Researches in Electricity, Volume 1 When the galvanometer was introduced into the circuit at the same time with the iodide, it was with difficulty that the action of the current on it could be rendered sensible. Experimental Researches in Electricity, Volume 1 Perchloride of tin, chloride of arsenic, and the hydrated chloride of arsenic, being liquids, had no sensible conducting power indicated by the galvanometer, nor were they decomposed. Experimental Researches in Electricity, Volume 1 Green bottle-glass, heated in the same manner, did not gain conducting power sensible to the galvanometer. Experimental Researches in Electricity, Volume 1 |
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