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VI. The Bakerian Lecture. —Experimental Researches in Electricity.—Second 
Series. By Michael Faraday, F.R.S., M.R.I., Corr. Mem. Royal Acad, of 
Sciences of Paris, Petersburgh, fyc. 8$c. 
Read January 12, 1832. 
§ 5. Terrestrial Magneto-electric Induction. 
§ 6. Force and Direction of Magneto-electric Induction generally. 
5. Terrestrial Magneto-electric Induction. 
140. "WHEN the general facts described in the former paper were discovered, 
and the law of magneto-electric induction relative to direction was ascertained 
(114.), it was not difficult to perceive that the earth would produce the same 
effect as a magnet, and to an extent that would, perhaps, render it available in 
the construction of new electrical machines. The following are some of the 
results obtained in pursuance of this view. 
141. The hollow helix already described (6.) was connected with the galva¬ 
nometer by wires eight feet long; and the soft iron cylinder (34.), after being 
heated red hot, and slowly cooled, to remove all traces of magnetism, was 
put into the helix so as to project equally at both ends, and fixed there. The 
combined helix and bar were held in the magnetic direction or line of dip, 
and (the galvanometer needle being motionless) were then inverted, so that 
the lower end should become the upper, but the whole still correspond to the 
magnetic direction ; the needle was immediately deflected. As it returned to 
its first position, the helix and bar were again inverted; and by doing this two 
or three times, making the inversions and vibrations to coincide, the needle 
swung through an arc of 150° or 160°. 
142. When one end of the helix, which may be called A, was uppermost at 
first (B end consequently being below), then it mattered not in which direction 
it proceeded during the inversion, whether to the right hand or left hand, or 
through any other course; still the galvanometer needle passed in the same 
direction. Again, when B end was uppermost, the inversion of the helix and 
bar in any direction always caused the needle to be deflected the same way; 
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