274 Rev. Mr Scoresby 07i some of the Laws 



magnet on each of the particles of the iron, and the communi- 

 cative influence of the various magnetic particles in the bar 

 upon each other. Hence the energy with which the inductive 

 influence on the end of the bar nearest to the magnet is exhibit- 

 ed at the other. 



Of these two influences, this experiment seems to afford a sa- 

 tisfactory illustration. 



Experiment 1. — Illustratioti of the neutral condition of Iron, 

 and of the Direct and Communicated influence of induction, 

 A bar magnet, 12 inches in length, being placed in the direc- 

 tion of the west point of a small compass, at the distance of a 

 foot from its centre, produced a deviation in the needle of 

 39°.40'. Between the magnet and the compass I now placed, in 

 the manner represented in PL II. fig. 6. a, a series of six similar 

 pieces of iron-wire, previously softened in the fire, 1.7 inches in 

 length each, and j^^^th in diameter. The wires in this arrange- 

 ment being placed at right angles across the straight line joining 

 the magnet and compass, derived no polarity, because of their 

 position, and, consequently, could exhibit no influence ; the de- 

 viation, as expected, was therefore unaltered. Each piece of wire 

 being now turned on its centre, so as to preserve its relative dis- 

 tance, was next arranged without contact, as in series b, and 

 then the deviation was 43°.4r, being an increase through the 

 magnetism developed in the wires of 4°.!'. The pieces of wire 

 were, lastly, placed in contact in a straight hne, as in series c, 

 each piece being at the same distance both from the magnet and 

 compass as before, when the deviation was found to be 49°. 47', 

 being a farther increase, occasioned by the transmitted influence, 

 of 6°.6\ 



Suppose, now, these pieces of wire to represent separate mag- 

 netic particles, and they will be found very well to illustrate 

 the principal phenomena of induction. Under the parallel form 

 of Fig. 6. «, we have a representation of an unmagnetised bar of 

 iron, in which the particles, under the influence of their inherent 

 spontaneous attractions, are mutually neutralized. Under the 

 next form (b), we have an illustration of the proportion of di- 

 rect inductive influence of the proximate magnet, on all the se- 

 parate particles in the aggregate. And under the last form, of 



