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This historic book may have numerous typos, missing text or index. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. 1878. Not illustrated. Excerpt: ... 344. But by winding his coils longitudinally, or parallel to the axis of the core, and placing the armature so formed between the poles of a series of horseshoe magnets, Siemens obtained magneto-electric currents much more powerful than those of Saxton. Wilde's Machine. Things were in this state when, in 1866, Wilde made an important addition to our knowledge of magnetoelectricity. 345. He conducted the current obtained by means of Siemens's armature round an electro-magnet, and found that the magnetism thus excited was far greater than that of the entire series of steel magnets employed to generate the magneto-electric current. 346. Thus, in one case, he found that whereas the series of permanent magnets taken collectively was competent to support a weight of 40 lbs. only, the electromagnet which they excited sustained a weight of 1,088 lbs. 347. To produce this effect, however, it was necessary that the armature of the magneto-electric machine should rotate with great rapidity. 348. But Wilde went farther. Forming his electromagnet from a large plate of iron, and placing between its long poles a correspondingly long armature, similar in shape and construction to that of the magneto-electric machine, he obtained from this second armature currents of enormously greater power than those obtainable from the first. 349. These currents could in their turn be sent round a second electro-magnet, formed from a larger plate of iron. Furnished with a rotating armature, this second electromagnet produced effects previously unknown. Rods of iron a quarter of an inch in thickness were fused by the currents, and they were also found competent, when discharged between carbon terminals, to produce a light of intolerable brilliancy. Siemens's and Wheatstone's Machine. 350. The ...