Electro-magnetism: Being an Arrangement of the Principal Facts Hitherto Discovered in that Science. With Plates of the Apparatus |
Common terms and phrases
acid action amalgamated Ampére Ampére's antimony apparatus arrangement attraction aurora axis bismuth bodies brass wire centre chemical circuit conducting power conductor conjunctive wire connected connexion contrivance copper copper wire current of electricity cylinder deviation diameter direction duced effects elec electrical current electro-magnetic exhibited experiments extremity fact fastened figure fluid galvanic battery galvanometer glass grooves heat helix horse-shoe magnet immersed inches long induction instrument iron filings junctive wire length magnetic bar magnetic needle Marsh's ments mercury meridian metals meteor motion move multiplying wire negative netic nitrate nitric acid north pole Oersted opposite pairs of plates pass periments pheno phenomena piece placed plane platinum polarity positive produced Professor ratus rectangular revolve round right angles ring rotation side Sir Humphrey soldered solution south pole substance surface suspended temperature thermo-electric thermo-magnetism tion tism tricity trough turned vanic variation voltaic voltaic pile wheel zinc
Popular passages
Page 202 - No person can look into the world with the eye of a philosopher, and not soon ascertain that the grand theatre of phenomena which lies before him is naturally subdivided into two great classes of scenery : the one exhibiting constrained, the other voluntary motion ; the former characteristic of matter, the latter as clearly indicating something perfectly distinct from matter, and possessing totally opposite qualities.
Page 202 - Intellect and volition are quite of a different nature from corporeal figure or motion, and must reside in, or emanate from, a different kind of being, a kind which, to distinguish it from matter, is called spirit, or mind. Of these, the one is necessarily inert, the other essentially active. The one is...
Page 33 - In a very early stage of electro-magnetic experiments it had been suggested that an instantaneous telegraph might be established by means of conducting wires and compasses. The details of this contrivance are so obvious, and the...
Page 42 - ... same manner ; with only this difference, that the wire positively electrified was below. In this case the results were precisely the same, except that the poles were reversed ; and any body, moved in the circle from the north to the south pole of the same needle, had its direction from east to west. A number of needles were arranged as polygons in different circles round the same piece of paste-board, and made magnetic by electricity; and it was found that in all of them, whatever was the direction...
Page 37 - Masses of mercury of several inches in diameter were set in motion, and made to revolve in this manner, whenever the pole of the magnet was held near the perpendicular of the wire ; but when the pole was held above the mercury between the two wires, the circular motion ceased ; and currents took place in the mercury in opposite directions, one to the right, and the other to the left of the magnet.
Page 37 - I had two copper wires, of about one-sixth of an inch in diameter, the extremities of which were flat and carefully polished, passed through two holes three inches apart in the bottom of a glass basin, and perpendicular to it ; they were cemented into the basin, and made non-conductors by sealing-wax, except at their polished ends; the basin was then filled with mercury, which stood about a tenth or twelfth of an inch above the wires.
Page 42 - ... wire, its motion (beginning with the lower part of the circle) was from north to south, or with the upper part from south to north ; and when the needles were arranged round a cylinder of paste-board so as to cross the wire, and a pencil mark drawn in the direction of the poles, it formed a spiral. It was perfectly evident from these experiments, that as many polar arrangements may be formed as chords can be drawn in circles surrounding the wire; and so far these phenomena agree with your idea...
Page 35 - ... wires there would be any diminution in the electrical effect upon the needle. * * * Had it been found true that the galvanic fluid could be transmitted in a moment through a great extent of conducting wire without diminishing its magnetic effect, then no question could have been entertained as to the practicability and importance of the suggestion adverted to above with regard to the telegraph. Mr. Barlow, of the Royal Military Academy (at Woolwich), who has made a number of successful experiments...
Page 51 - ... and being well amalgamated, it, when in the cup, retains sufficient fluid mercury by capillary attraction to form an excellent contact with freedom of motion. The ball is prevented from falling out of the socket by a piece of fine thread, which, being fastened to it at the top, passes through a small hole at the summit of the cup, and is made fast on the outside of the thick wire. This is more minutely explained by figs.
Page 11 - ... production, were not obvious from them. When a magnet is made to act on steel filings, these filings arrange themselves in curves round the poles, but diverge in right lines; and in their adherence to each other form right lines, appearing as spicula. In the attraction of the filings round the wire in the Voltaic circuit, on the contrary, they form one coherent mass, which would probably be perfectly cylindrical were it not for the influence of gravity. In first considering the subject, it appeared...