disadvantages for another on account of
differences in the mental disposition. One man may write more quickly
on one, another on another machine. As every one knows, the chief
difference is that of the keyboard and that of the visible or
invisible writing. Machines like the Remington machine work with a
shift key; that is, a special key must be pressed when capital letters
are to be written. Other machines like the Oliver even demand double
shifting, one key for the capital letters, and one for the figures,
and so on. On the other hand, machines like the Smith Premier have no
shift key, but a double keyboard. It is evident that both the
shift-key arrangement and the double keyboard have their particular
psychological advantages.

The single alphabet demands much less from the optical memory, and the
corresponding motor inner attitude of consciousness is adjusted to a
smaller number of possibilities. But the pressure on the shift key,
which goes with the single alphabet, is not only a time-wasting act;
from the psychological point of view it is first of all a very strong
interruption of the uniform chain of impulses. If the capital and
small letters are written for a minute alternatingly with the greatest
possible speed, the experiment shows that the number of letters for
the machine with the double alphabet is about three times greater than
for the machine with simple alphabet and shift key. Both systems
accordingly have their psychological advantages and disadvantages.
Human beings of distinct visual ideational type or of highly developed
motor type will prefer the double alphabet, provided, of course, that
the touch system of writing is learned, and this will be especially
true if their inner attitude is easily disturbed by interruptions. But
those who have a feebly developed optical mental centre and who have
small ability for the development of complex motor habits will be more
efficient on the machines with the single alphabet, especially if
their nervous system is little molested by interruptions and thus
undisturbed by the intrusion of the shift key act.

In a similar way the visibility of the writing will be for certain
individuals the most valuable condition for quick writing, while for
others, who depend less upon visual support, it may mean rather a
distraction and an interference with the speediest work. The visible
writing attracts the involuntary attention, and thus forces
consciousness to stick to that