1913-14.] Analytical Study of the Mechanism of Writing. 233 
tracing arrangement differently to the metal strip, to keep the writing 
point against the surface of the paper by means of a spring, and to prevent 
such movement of the whole tracing arrangement as will tend to cause it 
either to fail to respond to any movement of the hand, or to interfere with 
the attention of the writer or his free hand movement. In the apparatus 
shown (fig. 1) these objects are secured by attaching a metal pin tangen- 
tially to the metal strip where it curves over on to the back of the hand, 
and fitting the tracing arrangement to a tube which passes over this pin 
and is movable along the pin, being fastened by a screw in any position 
that may be necessary for adjustment. All the joints are arranged for 
adjustment and not for free movement. Finally, by means of a spiral 
spring the tracing point after adjustment is kept in contact with the paper. 
The trace itself is given by a capillary glass tracing tube or by a lead 
pencil, the holder for which occupies the place of the tracing style in 
Judd’s apparatus. 
As an indication of the kind of work that may be done with this 
apparatus, some tracings are shown (fig. 2), but the results hitherto obtained 
may also be briefly summarised. 
1. Normally, in careful adult writing, and more especially in pen writing, 
the finer movements in the formation of the letters are due to the fingers. 
As the writing is increased in speed, the hand may take over a larger and 
larger share of the movement, until with very rapid writing the movements 
are sometimes nearly all hand movements. 
2. The main movement of the hand in writing is alternately a rotation 
about an axis in the wrist and about an axis in the elbow with careful 
