52 



MAGNETISM. 



vious possession of any magnet. As the 

 knowledge of it, therefore, may be of 

 use to those who are not provided with 

 any magnetic apparatus, we shall pre- 

 sent the following outline of that part 

 of it which appears to be the really effi- 

 cient process. 



(206.) Six bars of soft steel are to be 

 provided, each three inches long, one 

 quarter of an inch broad, and one twen- 

 tieth of an inch thick, together with two 

 pieces of iron, each half the length of 

 one of the bars, but of the same breadth 

 and thickness ; and also six bars of hard 

 steel, each five inches and a half long, 

 half an inch broad, and three twentieths 

 of an inch thick, together with two 

 pieces of iron of half the length, but the 

 whole breadth and thickness of one of 

 the hard bars. All these bars are to be 

 marked at one end by a line quite round 

 them, in order to distinguish the poles. 



(207.) Two bars of iron, or an iron 

 poker and tongs (Jig. 54), are to be taken : 



Fig. 54. 



the larger they are, and the longer they 

 have been used, so much the better. 

 Let the poker be fixed upright, and held 

 by the knees, and let one of the soft steel 

 bars, having its marked end downwards, 

 be tightly fastened to it by a piece of 

 sewing silk, and held with the left hand ; 

 then grasping the tongs with the right 

 hand a little below the middle, and hold- 

 ing them in a vertical position, let the 

 bar be rubbed with the lower end, from 

 the bottom to the top, about ten times 

 on each side. This will give it sufficient 

 magnetic power to lift a small key from 

 the marked end, which will, of course, 

 be a north pole. 



(208.) Having magnetized four of the 

 soft bars in this manner, the other two 

 (fig. 55) are to be laid parallel to each 

 other, at the distance of about one 

 fourth of an inch between the two 

 pieces of iron belonging to them, a north 

 and a south pole against each piece of 

 iron. Two of the four bars that have 

 been already made magnetical are then 

 to be united, so as to make a double bar 

 in thickness, the north pole of one even 

 with the south pole of the other ; and the 

 remaining two being placed next to 

 these, one on each side, so as to have 

 two north and two south poles together, 

 the north and south poles are to be se- 

 parated at one end by a large pin put 

 between them; they are then to be 



placed perpendicularly with that end 

 downwards, on the middle of one of the 

 parallel bars the two north poles to- 

 wards that end intended to be made the 

 south pole, and the two south poles to- 

 wards the intended north poles. Next 

 slide them backwards and forwards 

 three or four times the whole length of 

 the bar, and removing them from the 

 middle of this bar, place them on the 

 middle of the other bar as before di- 

 rected, and go over that in the same 

 manner. Then turn both the bars the 

 other side upwards, and repeat the ope- 

 ration. 



Having done this, remove the two 

 bars from between the pieces of iron, 

 and placing the two outermost of the 

 touching bars in their stead, let the 

 other two be the outermost of the four 

 to touch these with. This process being 

 repeated till each pair of bars have been 

 touched three or four times over, they 

 will thus acquire a considerable magnetic 

 power. 



Next put together the six bars, as 

 was done with the four, and touch 



