Measurement And Its Appliances





The appliances necessary for the work of examination are, a good

magnifying or reading glass of the greatest power obtainable, a pair of

fine compasses or dividers, a horn or celluloid protractor for measuring

angles of slope, and a clearly marked scale rule. Suitable articles will

generally be found in an ordinary case of mathematical instruments.



A simpler and equally accurate method of taking measurements of

handwriting is by the aid of the transparent paper known as foreign

letter paper. It is usually of quarto size, very thin and transparent,

and is ruled horizontally and vertically, dividing the sheet into tiny

squares. It is laid over the writing to be examined, and the various

measurement marks are made with a finely pointed lead pencil. The lines

and squares are used for measurement as the parallels of latitude and

longitude are used on a chart. For example, a letter is said to be so

many lines high, so many lines wide. One of the tiny squares should be

carefully divided into two, or, if possible, four parts, so as to ensure

finer and more accurate measurement. A letter may then be measured in

parts of a line, being described, for example, as, height 6-3/4 lines,

breadth 2-1/2 lines. It is of course important that the same gauge of

ruled paper be used uniformly, otherwise the measurements will vary. If

the student has had practice in the use of the dividers and scale rule,

he may prefer to employ these, but the ruled paper and a finely pointed

lead pencil will be found sufficient for most purposes. A paper

specially prepared for surveyors, ruled in squares of one-eighth of an

inch may be obtained. For measuring the slopes of letters a transparent

protractor is necessary. The letters measured are all topped and tailed

small letters, and all capitals having a shank. Letters like _O_, _C_,

_Q_, _S_, and _X_ can only be measured approximately.



The method of applying the measurements of heights and angles of slope

is shown in the case illustrated by the table on page 15.



The subject of enquiry was a signature containing the letters _B_, _l_,

_k_, _b_.



The measurements of these letters in the forgery are given at the top of

the table, and show the height in lines and angle of slope in degrees.



The measurements of the corresponding letters in twelve genuine

signatures are shown in the table as Examples 1 to 12.



The total is averaged by dividing by twelve.



The presumption in favour of the suspected signature being a forgery is

strongly supported by the arithmetical result.



A difference of more than 2 per cent. in angle of slope, and 3 per cent.

in height may be safely relied upon as ground for suspicion, for it is

rarely that a man's signature varies so greatly within a brief period.

In the absence of the explanation provided by illness, intentional

change in style or other abnormal circumstances, such a difference as is

shown in this example will justify a belief that the suspected signature

is by another hand.



---------+-------------------------------++-------------------------------

Height in lines. Angle of slope.

+-------+-------+-------+-------++-------+-------+-------+-------

_B._ _l._ _k._ _b._ _B._ _l._ _k._ _b._

---------+-------+-------+-------+-------++-------+-------+-------+-------

Forgery 7 7 6 7-1/4 15 20 21 21

---------+-------+-------+-------+-------++-------+-------+-------+-------

Example 1 7-1/4 6-1/2 5-1/2 7-1/2 16 22 21 20



" 2 7-1/4 6-1/4 6 7-1/4 17 21 20 20



" 3 7-1/4 6 5-3/4 7-3/4 16 21 20 21



" 4 7 6-1/4 5-3/4 7-1/2 16 21 20 21



" 5 7 6-3/4 5-3/4 7-1/2 17 22 21 20



" 6 7-1/2 6-3/4 5 7-1/2 16 21 20 21



" 7 7-1/2 6 6 7-1/4 17 20 21 21



" 8 7-1/2 6-1/2 5-3/4 7-1/2 16 22 21 21



" 9 7-1/4 6-1/2 5-1/2 7 16 21 21 21



" 10 6-3/4 6-1/2 5-3/4 7-1/4 16 20 21 21



" 11 7-1/4 6-3/4 5-3/4 7-1/2 16 21 21 22



" 12 7 6-1/4 5-3/4 7-1/2 16 20 21 21

---------+-------+-------+-------+-------++-------+-------+-------+-------

Average 7-1/4 6-1/2 5-3/4 7-1/2 16-1/4 21 20-3/4 20-3/4

---------+-------+-------+-------+-------++-------+-------+-------+-------





Inks Paper And Watermarks facebooktwittergoogle_plusredditpinterestlinkedinmail

Feedback