Electro-magnetism: History of Davenport's Invention of the Application of Electro-magnetism to Machinery... Also, Extracts from Other Public Journals...G. & C. Carvill, 1837 - 94 pages |
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Page 9
... steam power , more readily appreciated the value of Mr. Davenport's invention , than could have been expected from many others . Struck with its value and importance on his first examination , Mr. Cook offered , from benevolent motives ...
... steam power , more readily appreciated the value of Mr. Davenport's invention , than could have been expected from many others . Struck with its value and importance on his first examination , Mr. Cook offered , from benevolent motives ...
Page 11
... to be expected that those whose interests and fortunes are embarked in the use of steam power , should feel very anxious for the success of this machine . Yet even in this class there are several whose benevolence desires the good 11.
... to be expected that those whose interests and fortunes are embarked in the use of steam power , should feel very anxious for the success of this machine . Yet even in this class there are several whose benevolence desires the good 11.
Page 14
... steam engine . This is the original application from which have sprung , or at least to which have succeeded , several similar attempts , both in this country and in Europe . A galvanic machine was reported to the British Association ...
... steam engine . This is the original application from which have sprung , or at least to which have succeeded , several similar attempts , both in this country and in Europe . A galvanic machine was reported to the British Association ...
Page 23
... steam engine of the same power . From the time when the Greek philosopher supposed the magnet possessed a soul , its mysterious power has been re- garded with increasing interest and attention to the present day . In addition to its ...
... steam engine of the same power . From the time when the Greek philosopher supposed the magnet possessed a soul , its mysterious power has been re- garded with increasing interest and attention to the present day . In addition to its ...
Page 24
... Steam Engine . His far - see- ing genius seems to have anticipated the invention of which we are speaking . " Philosophy , " said he , " already directs her finger at sources of inexhaustible power in the phenom- ena of electricity and ...
... Steam Engine . His far - see- ing genius seems to have anticipated the invention of which we are speaking . " Philosophy , " said he , " already directs her finger at sources of inexhaustible power in the phenom- ena of electricity and ...
Common terms and phrases
acid acidulated water agent apparatus application attraction and repulsion bodies chemical action chemical decomposition circle common electricity conductors consequently Cook copper slip copper wire current of electricity cylinder Davenport deflected direction discovery distance earth effects elec electric currents electric fluid electro-dynamics electro-magnetic energy engine equilibrium exhibited experiments Faraday feeble galvanic battery galvanic magnet galvanometer heat helix inches increase indefinitely induction insulated intensity invention iron cross kind of electricity machinery magnetic needle magnetic pole magnetised material matter mechanical ment metallic moving mysterious negative electricity netic neutral north pole observed opposite particles patent phenomena plate polarity positive electricity pounds Princeton College principle produced properties quantity of electricity repel revolutions per minute revolve right angles rotary motion rotation soft iron solar light south pole steam steel substances subtile surface suspended terrestrial magnetism theory Thomas Davenport tion tricity voltaic electricity zinc
Popular passages
Page 49 - Suppose that the two extremities of a cloud highly charged with electricity hang down towards the earth ; they will repel the electricity from the earth's surface, if it be of the same kind with their own, and will attract the other kind ; and, if a discharge should suddenly take place at one end of the cloud, the equilibrium will instantly be restored by a flash at that point of the earth which is under the other. Though...
Page 88 - Hence arises still further confirmation, if any were required, of the identity of common and voltaic electricity, and that the differences of intensity and quantity are quite sufficient to account for what were supposed to be their distinctive qualities.
Page 85 - ... to complete the circuit, these currents could not exist. Since the motion, not only of metals but even of fluids, when under the influence of powerful magnets, evolves electricity, it is probable that the gulf stream may exert a sensible influence upon the forms of the lines of magnetic variation, in consequence of electric currents moving across it, by the electro-magnetic induction of the earth.
Page 56 - There are places where the magnetic meridian coincides with the terrestrial meridian ; in these a magnetic needle freely suspended points to the true north; but if it be carried successively to different places on the earth's surface, its direction will deviate sometimes to the east and sometimes to the west of north. Lines drawn on the globe, through all the places where the needle points due north and south, are called lines of no variation, and they are extremely complicated.
Page 16 - But it is an important fact, discovered by experience, that the latter is soon impaired in its power by the influence of the revolving galvanic magnet, which is easily made to surpass it in energy, and thus, as it were, to overpower it. It is obvious, therefore, that the fixed magnet, as well as the revolving, ought to be magnetized by galvanism, and then there is every reason to believe that the relative equality of the two, and of course their relative energy, may be permanently supported, and...
Page 17 - The entire apparatus is therefore constructed of soft unmagnetic iron, which being properly wound with insulated copper wire, is magnetized in an instant, by the power of a very small battery. The machine is indeed the identical one used before, except that the exterior circle of permanent magnets is removed and in its place is arranged a circle of soft iron, divided into two portions to form the poles. These semicircles are made of hoop iron, one inch in width, and one eighth of an inch in thickness.
Page 80 - The electro-magnetic effect of the elective current induced in a conductor by a magnetic pole, in consequence of their relative motion, is such as tends continually to diminish that relative motion ; that is, to bring the moving bodies into a state of relative rest : so that, if the one be made to revolve by an extraneous force, the other will tend to revolve with it, in the same direction, and with the same velocity.
Page 48 - ... that they owe their existence, or at least their form, to that fluid. It is very probable that when two currents of dry air are moving different ways, the friction of the two surfaces may evolve electricity. Should these currents be of different temperatures, a portion of the...
Page 48 - When two clouds, charged with opposite kinds, approach -within a certain distance, the thickness of the coating of electricity increases on the two sides of the clouds that are nearest to one another ; and when the accumulation becomes so great as to overcome the coercive pressure of the atmosphere, a discharge takes place, which occasions a flash of lightning. The actual quantity of electricity in any...
Page 21 - Thomas Davenport. In the words of the patent, taken out, this invention " consists in applying magnetic and electro-magnetic power as a moving principle for machinery, in the manner described, or in any other substantially the same in principle.