5G2 Capt. Scoresby’s Description qf a Magnetimeter. 
means, if the bar be held in the plane of the magnetic equa- 
tor. 
7. Iron heated to redness, and quenched in water, in a verti- 
cal position, becomes magnetic ; the upper end gaining south 
polarity, and the lower end north. 
8. Hot iron receives more magnetism of position than the 
same when cold. 
9. A bar-magnet, if hammered when in a vertical position, 
or in the position of the magnetic axis, has it power increased, 
if the south pole be upward, and loses some of its magnetism if 
the north end be upward. 
10. A bar of soft steel, without magnetic virtue, has its mag- 
netism of position fixed in it, by hammering it when in a verti- 
cal position ; and loses its magnetism by being struck when in 
the plane of the magnetic equator. 
11. An electrical discharge, made to pass through a bar of 
iron^ devoid of magnetism, when nearly in the position of the 
magnetic axis, renders the bar magnetic; the upper end becoming 
a south pole, and the lower end a north pole ; but the discharge 
does not produce any polarity, if the iron be placed in the 
plane of the magnetic equator. The effects appear to be the 
same, whether the discharge be made on the lower or upper end 
of the bar, or whether it is passed longitudinally or transverse- 
ly through the iron. 
12. A bar of iron possessing some magnetism, has its polarity 
diminished, destroyed, or inverted, if an electric discharge be 
passed through it, when it is nearly in the position of the 
magnetic axis, provided the south pole of the bar be downward ; 
while its magnetism is weakened or destroyed, if it receive the 
shock when in the plane of the magnetic equator. 
13. Iron is rendered magnetical, if a stream of the electric 
fluid be passed through it, when it is in a position nearly corre- 
sponding with that of the magnetic axis ; but no effect is pro- 
duced, when the iron is in the plane of the magnetic equator, 
