... On Recent Improvements in the Chemical Arts, Том 2,Выпуск 1

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Smithsonian institution, 1862 - Всего страниц: 216

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Стр. 23 - quantity" magnets were introduced to avoid circumlocution, and were intended to be used merely in a technical sense. By the intensity magnet I designated a piece of soft iron, so surrounded with wire that its magnetic power could be called into operation by an intensity battery, and by a quantity magnet, a piece of iron so surrounded by a number of separate coils, that its magnetism could be fully developed by a quantity battery.
Стр. 33 - I had previously given to my class at Princeton. . . . The object of Professor Wheatstone as I understood it, in bringing into action a second circuit, was to provide a remedy for the diminution of force in a long circuit. My object in the process described by me was to bring into operation a large quantity magnet connected with a quantity battery in a local circuit, by means of a small intensity magnet and an intensity battery at a distance.
Стр. 58 - ... series of blotches, alternating with the lowest already mentioned. The throat and chin are unspotted. The head is light brown, with a narrow whitish line finely margined before and behind with black, which crosses in front of the centre of the vertical, and through the middle of the superciliaries : a second similar but more indistinct line runs parallel to this, just behind the rostral, and extending down in front of the eye. A third equally indistinct and similar line crosses the posterior...
Стр. 10 - C. WALKER, and the statement of Mr. Morse's own associate, Dr. GALE. Mr. Morse further maintains, that all discoveries bearing upon the telegraph were made, not by Professor Henry, but by others, and prior to any experiments of Professor Henry in the science of electro-magnetism ; contradicting in this proposition the facts in the history of scientific discovery perfectly established and recognized throughout the scientific world. The essence of the charges against Prof.
Стр. 23 - the first to point out this connection of the two kinds of the battery with the two forms of the magnet, in my paper in Silliman's Journal, January, 1831, and clearly to state that when magnetism was to be developed by means of a compound battery, one long coil was to be employed, and when the maximum effect was to be produced by a single battery, a number of strands were to be used.
Стр. 24 - But be this as it may, the fact, that the magnetic action of a current from a trough is, at least, not sensibly diminished by passing through a long wire, is directly applicable to Mr. Barlow's project of forming an electro-magnetic telegraph;* and it is also of material consequence in the construction of the galvanic coil.
Стр. 23 - ... introduction of the magnet to telegraphic purposes. Neither the electro-magnet of Sturgeon nor any electro-magnet ever made previous to my investigations was applicable to transmitting power to a distance.
Стр. 25 - I should state, however, that the arrangement that I have described was merely a temporary one, and that I had no idea at the time of abandoning my researches for the practical application of the telegraph. Indeed, my experiments on the transmission of power to a distance were superseded by the investigation of the remarkable phenomena, which I had discovered in the course of these experiments, of the induction of a current in a long wire on itself, and of which I made the first mention in a paper...
Стр. 12 - to Professor Henry is unquestionably due the honor of the discovery of a principle which proves the practicability of exciting magnetism through a long coil, or at a distance, either to deflect a needle or to magnetize soft iron.
Стр. 32 - I was called to the chair of natural philosophy in the College of New Jersey, at Princeton, and in my first course of lectures in that institution, in 1833, and in every subsequent year during my connexion with that institution, I mentioned the project of the electromagnetic telegraph, and explained how the electro-magnet might be used to produce mechanical effects at a distance adequate to making signals of various kinds.

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