MAGNETIC EXPERIMENTS. 
53 
the process is to hammer an iron or steel poker, 
or other rod of similar metal, of considerable size, 
while held in a vertical position, or, what is bet¬ 
ter, in the direction of the dipping-needle, by a 
few smart blows on the end; this will render the 
rod or poker sensibly magnetic. If a soft steel 
bar be now placed on the top of the poker, and 
hammered on the upper end, while both the 
poker and the bar are held vertically, or in the 
direction the dipping-needle assumes, it imme¬ 
diately, acquires a considerable attractive force, the 
upper end becoming a south pole, and the lower 
end a north pole. 
A cylindrical bar of soft steel, (i-J- inches long, 
a quarter of an incli in diameter, and 592 grains 
in weight, thus treated, acquired, in one instance, 
a lifting power of about 40 grains by a single blow 
with a hammer weighing 12 ounces ; and after ten 
blows (part of them given with a hammer a little 
larger), it lifted a nail weighing 188 grains ! But 
a still more extraordinary effect was obtained by 
the use of steel-wire. A piece of a knitting-needle, 
three inches in length, and weighing 28 grains, 
which was proved to be without anymagnetievirtue 
whatever before the experiment, on being repeat¬ 
edly hammered when held vertically on the top of 
a kitchen poker, lifted a nail of 54 grains, or very 
nearly twice its own weight! This singular pro- 
