Judge Chase was defended by the ablest lawyers in the country, including Luther Martin, Robert Goodloe Harper (1765-1825), Philip Barton Key (1757-1815), Charles Lee (1758-1815), and Joseph Hopkinson (1770-1842).
Hopkinson supplied a precise meaning (Phil.
The small magnet may be a sphere rigidly magnetized in the direction of Ho; if this is replaced by an isotropic sphere inductively magnetized by the field, then, for a displacement so small that the magnetization of the sphere may be regarded as unchanged, we shall have dW = - vIdHo = v I+-, whence W = - 2 I + H2 ° (37) The mechanical force acting on the sphere in the direction of displacement x is 1 Hopkinson specified the retentiveness by the numerical value of the " residual induction " (=47rI).
Trans., 188 5, 1 7 6, 549; Hopkinson, Phil.
Hopkinson pointed out that the greatest dissipation of energy which can be caused by a to-and-fro reversal is approximately represented by Coercive force X maximum induction fir.