*) 
4 
313 
The residual excitation, or power which remains after ex- 
citation has ceased, is always of the same amount, 130.68, if 
that would have passed half the maximum; below that it 
bears a continually increasing ratio to the full power till it be- 
comes two-thirds ofit. If, while the magnet is in this state, 
a current that would of itself produce the same lift be passed, 
the effect is not doubled, but only increased by one-third. A 
negative current, if powerful, destroys this condition ; if feeble, 
only lessens it. 
The least current which he has tried, 0.0008, excites the 
magnet, and even changes its residual magnetism. 
