186 
NAL OTS 
[APRIL 15, 1915 

is merely at the learning stage, there is little finger 
movement, but finger movements develop as facility 
is acquired. 
The isolation of grip pressure in writing is secured 

recording tambour. In Mr. Drever’s apparatus the 
pen or pencil is attached to a receiving tambour, which 
forms the top of the pen or pencil holder (Fig. 2). 
Fig. 2. 
This last form of apparatus is exceedingly simple and 
convenient for use with children. 
The study of the point pressure 
curve has already yielded some in- 
teresting results, which bear not only 
upon education but also on the study 
of mental defects. In normal adult 
writing two types of pressure curve 
were early and easily distinguished, 
and it is possible to distinguish three. 
The first, which is known as the mas- 
culine type, shows a single definite 
maximum of pressure for each word, 
and increased pressure with increased 
speed of writing (Fig. 3, IV.). The 
second, known as the feminine type, 

by an apparatus consisting essentially of a double- | shows several maxima of pressure in each word, and 
walled rubber capsule, inserted into the pen or pencil 
diminished pressure with increased speed of writing. 
holder to take the grip (Fig. 1). The space between ieee third, which might be called the clerical or 
the walls, and also the inner space, are filled. with 
mercury. A capillary 
glass tube passes into 
the inner space, and its 
top is connected by 
means of rubber tubing 
in the usual way with 
a recording tambour. 
Any variations in pres- 
sure on the outer wall 
of the capsule are in 
this way transmitted to 
the tambour and 
graphically recorded by 
the marking lever on a 
smoked drum. 
Very little work has 
hitherto been done in 
the study of grip pres- 
sure. The most striking 
feature in the grip pres- 
sure curve obtained is 
its rhythmical character 
(Fig. 3, VI). With the 
adult this rhythm is ex- 
tremely regular, but it 
is absent in the earliest 
writing of children, first 
appearing about the age 
of eleven, and then with 
marked irregularities 
(Fig. 3, VII.). In writ- 
ing with the pencil the 
grip pressure is con- 
siderably greater than 
in writing with the pen, 
and the difference be- 
tween maxima and 
minima in the rhythm 
also greater. Finally, 
there are in adult writ- 
ing definite indications 
that a word or even 
phrase is written with 
one total impulse. 
Several different 
forms of apparatus have 
been employed for ob- 
taining a record of point 
pressure in writing. Continental investigators have 
employed a writing plate, either connected directly 
with a lever for marking on a smoked surface, or 
resting on an air cushion pneumatically connected to a 
mechanical type, shows great uniformity of pressure 


I. to III. Point pressure tracings from children. Time record in seconds by Jacquet Chronograph. 
la. Child of six. Words ‘* The cow gives us milk.” 
14. Child of six (first attempt at script). Words ‘A man can.” 
Ic. Child of six (printing). Words ‘*A man can run” 
Ila. Pencil writing, and 11d. Pen writing of child of eight. Words ‘‘ Moray House School,” written twice in each case. 
III. Child of eleven. Pencil writing. Words ‘‘ Moray House School,” written twice. 
IV. and V. Point pressure tracings from adults. ‘lime record in } secs. by vibrating spring. 
IVa. Pencil writing, ordinary rate. Words ‘‘ Moray House School,” written twice. 
1V4. Pencil writing by same subject, maximum rate. 
Words “‘ Moray House School,” written fout times. 
V. Pen writing, slow and fast. Words ‘‘ Moray House School,” written once slow and twice fast. 
VI. and VII. Grip pressure tracings from adults and child of eleven. Time records for adults in } secs. and for child 
in secs. 
Via. Adult pencil writing. Words ‘‘ Moray House School.” 
Vlé. Adult pen writing. Words ‘‘ Moray House School Moray.” 
VII. Child's pencil writing. Words ‘‘ Moray House School” twice, slow and fast. 
NO. 2372, VOL. 95| 
in each word, and practically no change of pressure 
with increased speed of writing; further, there is 
comparatively little increase of speed beyond the 
ordinary rate, and in some cases the speed actually 
