De Magnete - Brossura

Gilbert, William

Brossura

ISBN 10: 048626761X ISBN 13: 9780486267616

Casa editrice: Dover Pubns, 1991

Riassunto

Much of modern science is based upon the theories and discoveries of William Gilbert, the brilliant English physician and physicist who was the first great experimental scientist. Gilbert was the first to use the word "electricity," to recognize mass as distinct from weight, to discover the effect of heat upon magnetic bodies, to differentiate clearly between static electricity and magnetism, and to explain phenomena of terrestrial magnetism in terms of the earth as a giant magnet.
In 1600 he published De Magnete in Latin. As lively and entertaining as it was scientifically scrupulous, it summarized everything that had previously been known about electricity and magnetism, founded a new science and earned Gilbert the title of "the father of modern electricity." In it Gilbert explores magnetism and electricity, lodestones, phenomena of magnetism, direction of the earth's magnetic lines of force, variation in the compass, dip, the concept of the earth as a giant magnet, and much else.
This Dover edition is a complete, unabridged reprinting of the definitive English translation of De Magnete prepared by Dr. P. Fleury Mottelay. Dr. Mottelay has added a number of footnotes that explain points that might be obscure to today's readers, who will find in this historically important text invaluable insights into the origins of modern science and physics. Translation by P. F. Mottelay. Biographical introduction. 90 illustrations.

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Contenuti:

Translator's Preface Biographical Memoir Address by Edward Wright Author's Preface Explanation of some Terms used in this Work Book I. I. Writings of ancient and modern authors concerning the loadstone: various opinions and delusions II. The loadstone: what it is: its discovery III. "The loadstone possesses parts differing in their natural powers , and has poles conspicuous for their properties" IV. Which pole is the north: how the north pole is distinguished from the south pole V. One loadstone appears to attract another in the natural position; but in the oppposite position repels it and brings it to rights. VI. The loadstone attracts iron ore as well as the smelted metal VII. What iron is; what its matter; its use VIII. In what countries and regions iron is produced IX. Iron ore attracts iron ore X. "Iron ore has and acquires poles, and arranges itself with reference to the earth's poles" XI. "Wrought-iron, not magnetized by the loadstone, attracts iron." XII. "A long piece of iron, even not magnetized, assumes a north and south direction" XIII. "Smelted iron has in itself fixed north and south parts, magnetic activity, verticity, and fixed vertices or poles" XIV. Of other properties of the loadstone and of its medicinal virtue XV. The medicinal power of the iron XVI. "That loadstone and iron ore are the same, and that ironis obtained from both, like other metals from their ores; and that all magnetic properties exist, though weaker, both in smelted iron and in iron ore" XVII. "That the terrestrial globe is magnetic and is a loadstone; and, just as in our hands the loadstone possesses all the primary powers (forces) of the earth, so the earth by reason of the same potencies lies ever in the same direction in the universe" BOOK II. I. Of magnetic movements II. "Of magnetic coition, and, first, of the attraction exerted by amber, or, more properly, the attachment of bodies to amber" III. "Opinions of others concerning magnetic coition, which they call attraction" IV. Of the strength of a loadstone and its form: the cause of coition V. In what manner the energy inheres in the loadstone VI. "How magnetized iron and smaller loadstones conform to the terrella, and to the earth itself, and are goverened thereby." VII. "Of potency of the magnetic force, and of its spherical extension" VIII. Of the geography of the earth and the terrella IX. Of the equinoctial circle of earth and terrella X. The earth's magnetic meridians XI. Parallels XII. The magnetic horizon XIII. Of the magnetic axis and poles XIV. Why the coition is stronger at the poles than in the parts between equator and pole; and the relative power of coition in different parts of the earth and the terrella XV. "The magnetic force imparted to iron is more apparent in an iron rod, than in an iron sphere, or cube, or iron of any other shape" XVI. That motion is produced by the magnetic force through solid bodies interposed: of the interposition of a plate of iron. XVII. "Of the iron helmet (cap) of the loadstone, wherewith it is armed at the pole to increase its energy; efficiency of the same" XVIII. An armed loadstone does not endow with greater force magnetized iron than does an unarmed one XIX. "That unition is stronger with an armed loadstone: heavier weights are thus lifted: the coition is not stronger, but commonly weaker" XX. "That an armed magnet lifts another, and that one a third: this holds good though there be less energy in the first" XXI. "That when paper or other medium is interposed, an armed loadstone does not lift more than one unarmed" XXII. "That an armed loadstone does not attract more than an unarmed one; and that the armed stone is more strongly united to the iron, is shown by means of an armed loadtone and a cylinder of polished iron" XXIII. "The magnetic force makes motion toward union, and when united connects firmly" XXIV. "That iron within the field of a loadstone hangs suspended in air, if on account of an obstacle it cannot come near" XXV. Intensifying the loadstone's forces XXVI. "Why the love of iron and loadstone appears greater than that of loadstone and loadstone, or iron and iron when nigh a loadstone and within its field" XXVII. That the centre of the magnetic forces in the earth is the centre of the earth; and in the terrella the terrella's centre XXVIII. "That a loadstone does not attract to a fixed point or pole only, but to every part of a terrella, except the equinoctial circle" XXIX. Of difference of forces dependent on quantity or mass XXX. The shape and the mass of an iron object are important magnetic coitions XXXI. Of oblong and round stones XXXII. "Some problems and magnetic experiments on the coition, and repulsion, and regular movement of magnetic bodies" XXXIII. Of the difference in the ratio of strength and movement of coition within the sphere of influence XXXIV. Why a loadstone is of different power in its poles as well in the north as in the south regions XXXV. "Of a perpetual-motion engine actuated by the attraction of a loadstone, mentioned by authors" XXXVI. How a strong loadstone may be recognized XXXVII. Uses of the loadstone as it affects iron XXXVIII. Of the attractions of other bodies XXXIX. Of mutually repellent bodies BOOK III. I. Of direction II. "Directive (or versorial) force, which we call verticity: what it is; how it resides in the loadstone; and how it is acquired when not naturally produced" III. "How iron acquires verticity from the loadstone, and how this verticity is lost or altered" IV. Why magnetized iron takes opposite verticity: and why iron touched by the true north side of the stone moves to the earth's north, and when touched by the true south side to the earth's south: iron rubbed with the north point of the stone does not turn to the south, nor vice versa, as all writers on the loadstone have erroneously thought V. Of magnetizing stones of different shapes VI. What seems to be a contrary movement of magnetic bodies is the regular tendence to union VII. "A determinate verticity and a directive power make magnetic bodies accord, and not an attractional or a repulsive force, nor strong coition along, or unition" VIII. Of disagreements between pieces of iron on the same pole of a loadstone; how they may come together and be conjoined IX. Directional figures showing the varieties of rotation X. "Of the mutation of verticity and magnetic properties, or of the alteration of the force awakened by the loadstone" XI. "Of friction of iron with the mid parts of a loadstone between the poles, and at the equinoctial circle of a terrella" XII. How verticity exists in all smelted iron not excited by the loadstone XIII. Why no other bodies save the magnetic are imbued with verticity by friction with a loadstone; and why no body not magnetic can impart and awaken that force XIV. "The position of a loadstone, now above, anon beneath, a magnetic body suspended in equilibrium, alters neither the force nor the verticity of the magnetic body" XV. "The poles, equator, centre, are permanent and stable in the unbroken loadstone, when it is reduced in size and a part taken away, they vary and occupy other positions" XVI. "If the south part of a loadstone have a part broken off, somewhat of power is taken away, they vary and occupy other positions" XVII. Of the use of rotay needles and their advantages; how the directive iron rotary needles and their advantages; how the directive iron rotary needles of sun-dials and the needlesof the mariner's compass are to be rubbed with loadstone in order to acquire stronger verticity BOOK IV. I. Of variation II. That variation is due to inequality among the earth's elevations III. Variation is constant at a given place IV. The arc of variation does not differ according to distance between places V. An island in ocean does not alter in variation; neither do mines of loadstone VI. "That variation and direction are due to the controlling force of the earth and the rotatory magnetic nature, not by an attraction or a coition or by other occult cause" VII. "Why the variation due to this lateral cause is not greater than hitherto it has been observed to be, seldom appearing to amount to two points of the compass, except near the poles" VIII. "Of the construction of the common mariner's compass, and of the different compasses of various nations" IX. Whether terrestrial longitude can be found from variation X. Why in various places near the pole the variations are much ampler than in lower latitudes XI. "Cardan's error in seeking to determine the distance of the earth's centre from the centre of the world by means of the loadstone (in his De Proportionbus, V)" XII. Of finding the amount of the variation; what the quantity is of the arc of the horizon from its arctic or antarctic intersection by a meridian to the point toward which the needle turns XIII. "Observations made by seamen commonly vary and are untrustworthy, partly though mistakes and want of knowledge and the imperfectness of the instruments, and partly because the sea is seldom so calm but shadows or lights may rest of the instruments" XIV. Of the variation under the equinoctial line and nearby XV. "The variation of the magnetized needle in the great sea, Ethiopic and American, below the equator" XVI. Of the variation in Nova Zembla XVII. Variation in the South Sea XVIII. Of the variation in the Mediterranean Sea XIX. The variation in the interior of the great continents XX. The variation in the Eastern Ocean XXI. How the deviation of the needle is greater or less according to the distance of places BOOK V. I. Of the dip of the magnetic needle II. Diagram showing dip of the magnetic needle in different positions of a sphere and horizons of the earth in which there is a variation of dip III. An instrument for showing by the action of a loadstone the degree of dip below the horizon in any latitude. Description of the instrument; its uses IV. Of a suitable length of needle on the terrella for showing the dip V. That dip is not caused by the attraction of a loadstone but by its power of giving direction and rotation VI. Of the ratio of the dip to latitude and the causes thereof VII. Explanation of the diagram of the rotation of magnetized iron. VIII. "Diagram of the rotation of magnetized iron showing the magnetic dip in all latitudes, and showing the latitude from the rotation and dip" IX. "Demonstration of direction, or of variation from the true direction, together with dip, simply by the movement in water, due to the power of controlling and rotating" X. Of variation of dip XI. Of the formal magnetic act spherically effused XII. "The magnetic force is animate,or imitates a soul; in many respects it surpasses the human soul while that is united to an organic body" BOOK VI. I. Of the globe of earth as a great loadstone II. The magnetic axis of the earth remains invariable III. "Of the daily magnetic revolution of the globes, as against the time-honored opinion of a primum mobile: a probable hypothesis" IV. That the earth hath a circular motion V. "Arguments of those who deny the earth's motion, and refutation thereof" VI. Of the cause of the definite time of the total revolution of the earth VII. Of the earth's primary magnetic nature whereby her poles are made different from the poles of the ecliptic VIII. Of the precession of the equiuoxes by reason of the magnetic movement of the earth's poles in the arctic and antarctic circle of the zodiac IX. Of the anomaly of the precession of the equinoxes and of the obliquity of the zodiac

Product Description:

From the first great experimental scientist: the classic text, first published in Latin in 1600, summarizing all then known about magnetism and electricity, offering invaluable insights into the origins of modern science. Topics include phenomena of magnetism, variation in the compass, and concept of Earth as a giant magnet.

Su questa edizione

• Editore: Dover Pubns
• Data di pubblicazione: 1991
• ISBN 10: 048626761X
• ISBN 13: 9780486267616
• Rilegatura: Copertina flessibile
• Numero di pagine: 427