antagonizing motion of one hand upon the other, which is likely to
produce an unintelligible scrawl, having little or none of the
habitual characteristics of either hand.

Where one hand is more or less passive, the controlling hand doing the
writing, its characteristics may be more or less manifest in the
writing. But obviously the controlling hand must be seriously
obstructed in its motions by even a passive hand; and since the
controlling hand can have no proper or customary rest, the motion must
be from the shoulder and with the whole arm. The writing will
therefore be upon an enlarged scale, loose, sprawling, and can have
little, if any, characteristic resemblance to the natural and habitual
style of the controlling writer, and of course none of the person's
whose hand is passive.

In appearance it changes abruptly from very high or very wide to very
low or narrow letters. This is to be explained by the non-agreement in
phase of the impulses due to each of the two writers. If both are
endeavoring at the same moment to write a given stroke the length of
that stroke will be measured by the sum of the impulses given by the
two writers. If they act in opposition to one another, one seeking to
make a down stroke while the other is trying to make an up stroke, the
result will be a line equal to the difference between the stronger and
the weaker force.

As these coincidences and oppositions occur at irregular but not
infrequent intervals, like the interference and amplification phases
of light and sound waves, the result traced on the paper might be
expected in advance to be--and in fact is--a distorted writing where
maxima and minima of effect are connected together by longer or