IMPROVEMENTS IN ENVELOPES
Year: 1882

page_text: LETTERS PATENT to Edmund Edwards, of the firm of Edwards and Co:-
Patent Agents and Engineers, of 40, Southampton Buildings, Chancery Lane,
in the County of Middlesex for an Invention of "IMPROVEMENTS IN
ENVELOPES" Communicated to him from abroad by Joseph Marzari, Achille
Manucci and Angelo Dalla Noce, all of Florence in the Kingdom of Italy
PROVISIONAL SPECIFICATION left by the said Edmund Edwards at the
Office of the Commissioners of Patents on the 16th November 1882.
"
EDMUND EDWARDS, of the firm of Edwards and Co-Patent Agents and'
Engineers, of 40, Southampton Buildings, Chancery Lane, in the County of
Middlesex "IMPROVEMENTS IN ENVELOPES [communicated to him from abroad
by Joseph Marzari, Achille Manucci and Angelo Dalla Noce, all of Florence in the
Kingdom of Italy]
This invention relates to envelopes of paper or other suitable material as
ordinarily made and used for the purpose of containing and protecting letters or
other articles, and it has for its object novel methods of making and using such
envelopes so that it is rendered difficult or impossible to open them when closed
and secured, without any attempt at such opening being at once perceptible.
The method most commonly adopted in fraudently opening envelopes containing
letters or valuables consists in moistening the gummed part with water or steam,
and subsequently adding gum and re-closing them. One part of the present
invention consists in rendering any such fraudulent treatment visible by applying
by means of a stamp or other convenient means to that part of the envelope which
must be moistened in order so to open it, one or more signs or letters in ink readily
soluble in water or other fluid. This ink in dissolving spreads and shows stains
which indicate the attempt which has been made. For this purpose a very thick
aniline ink may be used, and if it is desired that the envelope should not show the
signs or letters unless its opening has been attempted as described, an ordinary
sympathetic ink may be used the colour of which only becomes visible when

page_text: An easier method, however, than that above described for fraudulently opening
envelopes, though less known, consists in detaching the upper flap with the thumb
and first finger of the right hand whilst the thumb of the left hand holds firm the
lower flap against which the right thumb presses.
In this process it is not the paper of the upper flap but of the lower one which
splits, so that by regumming and closing the envelope again no trace remains
visible.
It is necessary, therefore, so to prepare the envelope that any effort to separate
the upper flap causes visible tears, or that the right thumb should find no sufficient
resistance in the lower flap to separate the upper one.
In another though less certain method of fraudulently opening envelopes, a thin
blade is carefully introduced between the gummed flaps in order to separate them.
Another part of this invention consists of novel methods of making and using
envelopes to prevent these fraudulent methods of opening them.
For this purpose the fixed flaps of the envelope have a sufficient number of slits,
cuts, or holes, made round their edges in different directions and in such position
that the edge of the moveable flap: when closed only partly covers them, their
remaining uncovered part being untouched by the gum, and visible outside the
edge of the flap.
If, therefore, any attempt is made to open the envelope, the parts between the
slits or holes tear and show marks of such attempt, whilst if slits or holes are
made in the gummed parts of the. flaps in order to weaken the substance of the
paper so that it may give way and tear, they would be almost useless as they
would be strengthened by becoming filled with the gum and the torn off surface of
the lower flap.
The slits or holes may also be made in the upper flap, provided that the gum is
not brought to its-edge which should be left free for a sufficient width such free
edge being also provided with slits.
By making a number of perforations in the upper flap the introduction of a blade
between the two flaps becomes still more difficult, although the slits and holes in
the lower flap alone as described are sufficient in most cases.
In another novel method of making the envelope for the purpose described, it is
formed partly with a square piece of cloth or woven fabric cemented upon a corre-
sponding square piece of paper upon which the four flaps forming the front of the
envelope are united.
Slits or holes through them as already described, serve to prevent the fraudulent
opening of the envelope either with a blade or with the hand.
Although the slits or holes are made in the upper flaps, if the latter are gummed
to the cloth and not to the paper the splitting of the covered flap is not observed
for on any attempt at opening the cloth does not leave a part of itself on the upper
flap to fill and strengthen the slits or holes, but the paper splits and tears off,
adhering to the cloth, without its being possible to conceal the injury by regumming
and closing the envelope again.
Another method of obtaining the same result consists in gumming the edge of
the upper flap upon the edge of the lower flap which is first turned back upon itself,
its outer edge extending slightly beyond the upper flap which is only attached to
the envelope by some projections extending beyond the turned back edge of the
fixed flap.
The extremities of the upper and lower flaps remain more or less separated from
the envelope, and by this arrangement the left thumb has no support to hold fast
the lower flap, whilst the right thumb is separating the upper flap from it, or vice
versd. The addition of slits in the lower flap makes the operation still more
difficult either by the hand or with a blade.
In another modification for the same purpose, slits and holes may be used as
already described, and in addition the point of the lower flap is folded back and is
then turned down and gummed upon the upper flap. when the latter has been
gummed-down-in-its-place-in-the-usual_way.__

page_text: In the different arrangements described, where slits, or holes are used in the
gummed parts, spaces should be left to receive the signs or letters in ink which
serve as already described to show any attempt to open the envelope by moisture.
By this invention, any attempt at opening the envelope becomes visible, if
moisture is used by the marks which it causes, or if the hand or an instrument is
used by the tearing of the paper where it is weakened by the slits or holes which
takes place where the paper is placed upon cloth or other woven fabric or com-
pressed paper or other material which will not split such as indiarubber, or upon
ordinary paper if the slits, or holes are made to extend beyond the gum and no
support is available to enable the hand to effect separation of the two flaps.
The different forms of envelope described, and the materials of which they are
made may be varied to suit varying circumstances.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Edmund Edwards in the Great Seal Patent Office on the
16th May 1883.
EDMUND EDWARDS, of the firm of Edwards and Co-Patent Agents and
Engineers, of 40, Southampton Buildings, Chancery Lane, in the County of
Middlesex "IMPROVEMENTS IN ENVELOPES" (A Communication to mo from
abroad by Joseph Marzari, Achille Manucci, and Angelo Dalla Noce, all of Florence
in the Kingdom of Italy)
This invention relates to envelopes of paper or other suitable material as
ordinarily made and used for the purpose of containing and protecting letters or
other articles, and it has for its object novel methods of making and using such
envelopes so that it is rendered difficult or impossible to open them when closed
or secured, without any attempt at such opening being at once perceptible.
Envelopes containing letters or telegrams or other valuable documents can be
fraudulently opened in three ways:-First, by means of a blade inserted between
the gummed flaps; Second, by moistening the flaps with water or steam; Third,
by separating with the finger and thumb of the right hand the upper flap whilst
with the thumb of the left hand the lower flap is held firm, a process little known
but very easy.
After such opening the envelope can be regummed and closed
without leaving any mark.
Several methods of rendering permanently visible any such fraudulent opening
can be used, and these methods are applicable to to different kinds of envelopes so as
to be available for different objects such as economy and the various uses to which
they are to be applied. For example, for business letters, despatches, and for the
different kinds of paper ordinarily sold.
The first part of the invention is illustrated in figure 1 of the accompanying
drawing, in which the upper flap a of the envelope is pierced with a series of holes
or cuts b, c, which may be varied as desired. The gum in this form of envelope is
applied so that it shews a series of intervals or grooves, for if the paper is
weakened by the holes in the gummed part in order that it may tear when an
attempt is made to open it with the thumb the holes would be almost useless.
In fact if it is attempted to separate one flap from the other, it is not the
paper of the upper but of the lower flap which splits, so that the holes which are
surrounded with the gum remain closed and thickened by the layer of paper split
off from the lower flap.
An examination of this result shows that at least some of the holes should be
separated from the action of the gum, in order that they may let the paper tear
when an attempt is made to open it.
To avoid the difficulty of applying the gum, the holes may be made in the lower
flap d, but so that part of them remain outside the gum. In this kind of
envelope, opening by means of moisture may be prevented by applying as easily
as the gum is applied, a line or marks of strong aniline ink or other very soluble
chemical substance of the like kind, either between the gum and the paper or on
the upper surface of the flap of the envelope. It is evident that this ink spreads
very freely under the action of moisture and so leaves marks of any fraudulent
attempt at opening.
J
manufactura instead of ink o special cum may be

page_text: employed containing a substance of the kind described, which will only spread
when the gum is dissolved by water.
The required weakening of the paper may be obtained by employing, instead of
holes, a chemical agent corroding or destroying the size in the paper, but always
with the same necessity (in order to render the weakening effective) for applying
the gum in grooves or intervals.
The same object may also be attained without either the use of holes or chemical
agents. If paper is united to cloth or linen by means of pressure, and the
envelopes are made from the compound material, as shewn in figure 4, so that the
cloth or linen is outside when the envelope is folded, if any attempt is made to
open it the paper of the upper flap being gummed upon the cloth of the lower flap
the splitting of such lower flap no longer takes place as the cloth cannot leave any
part of its substance upon the upper flap, but on the contrary the paper splits and
tears and is transferred to the cloth. If therefore the cloth which remains free
from paper in many places is regummed, the cloth shows the gum outside; and if
an attempt is made to open it by means of moisture the cloth loses the gloss which
it had acquired when pressed and becomes wrinkled, and these two effects are
very easily seen.
Figure 2 represents a modified form of this method of manufacture consisting of
an envelope which instead of being covered with cloth or linen is formed with a
square of cloth e, e, e, e, united by pressure to a corresponding square of paper upon
which close the four flaps f. f. f. f.
Holes are made in these four flaps and render fraudulent opening impossible,
for although the holes are made in the gummed part of the envelope this gummed
part being on the cloth and not on the paper the splitting of the lower flap no
longer takes place but it is the upper paper flap which splits and tears. In order
to prevent the use of moisture the same means are employed as in the envelope
shewn in figure 1.
Instead of a square of cloth, a small piece may be used, as shewn at g, g, in
figure 3, gummed on the lateral flaps, partly covered by the end h of the lower
flap k, and upon which is applied the upper flap of the envelope weakened in the
methods already described. In the kinds of envelopes in which the cloth is used as
described, very strong and good paper or other suitable material may be used
instead, which cannot split as the weaker paper splits in preference.
Figure 5 shews another modification of the methods already described and shewn,
in which in addition to holes like those in the others, a turned back piece 7, 1, is
added on the flap i, which is gummed upon the flap m which had already closed
the envelope.
In the form shewn in figure 6 the upper flap p is gummed upon the turned back
edges n, m, n, of the fixed flaps o, o, o. These turned back edges project a little
beyond the upper flap p which is gumined down at the points where the turned back
edges end, in order that it may not be distorted.
By this method of arrangement the thumb of the left hand has no sufficient
support to hold firm the lower flap whilst the thumb of the right hand separates
the upper flap, or vice versa. Figure 7 only differs from figure 6 in shewing the
method of applying this system to square envelopes.
In this description of envelope the weakening of the flaps as first described is
unnecessary.
It will be seen that this invention as hereinbefore described and shewn in the
drawing, is based upon the necessity in order to prevent the fraudulent opening of
envelopes either of employing cloth together with paper, or if paper is employed
alone of weakening it in such manner that part of the paper so weakened is not
re-strengthened by the action of the gum or by the splitting of the paper beneath;
or, if paper alone and unweakened be employed, of arranging it so that there is no
point of resistance by which one flap can be separated from the other. Also, of
indicating any attempt to open envelopes by the use of moisture; and having

page_text: described the invention and the manner in which it is to be performed, I claim:-)
the methods of making envelopes for the said purposes substantially as hereinbefore
described and shewn in the drawing.
In witness whereof, I, the said Edmund Edwards, have hereunto set my
hand and seal this sixteenth day of May in the year of our Lord 1883.
EDMUND EDWARDS (L.S.)'