Improvements in the Method of Displaying Advertisements, Notices, and the like.
Year: 1886

page_text: Date of Application, 23rd Aug., 1886.
Complete Left, 23rd May, 1887.
Complete Accepted, 24th June, 1887.
Improvements in the Method of Displaying Advertisements, Notices,
and the like.
I JOHN ST. CLAIR, of the Ewart, Nowton Stewart, in the county of Wigtown,
North Britain, Head Master of the Ewart High School, do hereby declare the nature
of this invention to be as follows:-
This invention consists in the application of the principle of personal equation in
the display of advertisements, notices and the like when either the eye or the
advertisement or notice is in rapid motion whereby the effects of that rapid motion
and the average personal equation are counteracted, the personal equation being the
amount of time required by each individual actually to see what he looks at. This
varies in each person but its average has been found to be about one tenth of a
second.
Now all notices on railways to drivers and guards, all names of stations, and all
advertisements are in the ordinary forms of lettering and cannot be read when the
train is at speed but are only guessed at when placed at a distance from the line; but
if each letter and part of letter and interspace be sufficiently distorted or extended
laterally so as to allow the eye of a person on the engine or in the train to rest on
each letter and part of lettor for the requisite time namely, about one tenth of a second
more or less, the whole however near to the eye becomes as legible as ordinary print
is when the eye is at rest. This lateral distortion is to be calculated in direct proportion
to speed and in inverse proportion to the distance from the eye and counteracts
the two disturbing elements of speed and personal equation so as to eliminate their
effects.
At the estimated distance traversed in one second it will be advantageous to place
some glittering object both before and after the notice, on the same level, as an eye-
catcher.
Although it is of much less importance when the eye is at rest and the notice is in
motion, as in the case of railway carriages before they have come to a stand, the same
oxpedient of sufficient lateral distortion produces the same useful effect of easy and
certain legibility.

page_text: COMPLETE SPECIFICATION.
Improvements in the Method of Displaying Advertisements, Notices,
and the like.
I, JOHN ST. CLAIR, of the Ewart, Newton Stewart, in the county of Wigtown,
North Britain, Head Master of the Ewart High School, do hereby declare the naturo
of this invention and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement :—
This invention consists in the application of the principle of personal equation in
the display of advertisements, notices and the like when either the eye or the
advertisement or notice is in rapid motion whereby the effects of that rapid motion
and the average personal equation are counteracted, the personal equation being tho
amount of time required by each individual actually to see what he looks at.
Hitherto all notices, directions, names of stations and advertisements on railways
have been formed with the aim of being as legible as possible to an eye at rest. But
such words however legible to an oye at rest, become first partially, and then wholly
illegible from a moving train in direct proportion to the train's rate of motion, this
loss of legibility arising from the fact that the average human eye requires about one
tenth of a second more or less according to each man's personal equation in order to
actually see what it looks at and keeps that impression about the same tin.e after the
object seen has passed away. This disturbing fact of personal equation has never yet
been provided against or taken into account and all notices, &c., intended to be read
by an eye in motion have been formed as if that optical peculiarity did not exist.
To meet this difficulty I produce a certain intentional illegibility of form to an eye
at rest so adapted to the speed of a train, that the same peculiarity of the eye which,
combined with rapid notion, makes all other legible words illegible, brings my illegible
words, by optical illusion, into the appearance of a form easily legible by every official
or passenger in any train however fast its motion. Hitherto logible forms have been
used and illegible effects produced but I use illegible forms to produce a legible effect.
This conversion of appropriate illegibility into legibility by suitable rapid motion is
the opposite of the universally practised conversion of legibility of form into illegibility
of impression by rapid motion. It is the same optical peculiarity along with rapid
motion that produces in the same way and at the same time these two opposite changes
or effects.
In order to carry my invention into practice it must first be calculated what
horizontal extension each space and each portion of a letter must have in order to be
about one tenth of a second before the eye at given rate of speed. This minimum
breadth must be in direct proportion to the speed but in inverse proportion to the
distance at which the words are placed back from the train.
All spaces and vertical lines must have at least the minimum breadth thus determined
to be requisite for distinct vision, but romain unaltered in height, while all horizontal
lines have their length similarly increased while their breadth is to be not at all effected.
These changes so distort each letter as to render the words altogether or almost

page_text: illegible to any one in a standing train. It requires the motion to reduce them to
apparent legible form.
In the accompanying drawing I have shewn how my invention may be carried into
practice but it will be understood that the drawing is merely given as an illustration.
As speed and distance from the train act inversely to each other, it follows that the
same forms may be adapted to higher rates of speed by setting them back to a greater
distance and vice versa.
While the amount of lateral distortion required depends on the given average speed
of the trains at any point, yet from a quicker train the words are still legible, though
apparently compressed while from a slower train they are still legible though apparently
extended. The same differences are experienced by eyes either much quicker or
much slower in susceptibility than the average eye, the quickest eyes reading the
words as if they were too extended and the slowest as if too compressed. But all can
read them at or about the rate of speed for which they are adapted.
The same means are to be used to produce the same results when the words are in
notion and the eye at rest, as in the destinations and classes of railway carriages, so
that these may be distinctly read before the train comes to a standstill.
At the estimated distance traversed in one second it will be advantageous to place
some glittering object both before and after the notice on the same level so as to form
an eye catcher. It will be obvious that this eye catcher, and, if desired, the notice
also, may be made to vibrate by motion communicated by the train through a wiro
passing over and under grooved pulleys and fixed to the lower part of the rail at one
end and to the eye catcher or notice at the other end. This motion may be increased
by fixing to and below the rail the short arm of a lever, pivotted on a bent bar
resting on the nearest sleeper, its longer arm operating the wire which moves the eyo
catcher or advertisement &c. At any change of direction in the wire, bell cranks may
be substituted for grooved pulleys.
Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed I declare that what I claim is :-
1. The method herein described of displaying advertisements, notices and the like
whereby the combination of the more rapid motion of a train with the total illegibility
of words, and the less rapid motion with their partial illegibility produced by lateral
extension is so adapted to the average personal equation that they become legible by
nicans of the same speed which makes all legible forms of words in the same
circumstances, illegible substantially as set forth."
2. An advertisement notice or the like, the lotters of which are so extended
laterally as to render the advertisement legible to persons in a train in motion, or
whon the advertisement is in motion the same shall be legible to an eye at rest
substantially as set forth and illustrated in the drawing.
3. The use in combination with an advertisement notice or the like of the kind
hereinbefore described and claimed of what I term an eye catcher either fixed or
having a vibrating motion which may be communicated to it by the motion of the
train substantially as and for the purpose set forth.