Improved Means or Apparatus for Marking Lines on Blackboards and other Surfaces.
Year: 1887

page_text: Date of Application, 26th Mar., 1887.
Complete Left, 13th Sept., 1887
Complete Accepted, 14th Oct., 1887.
Improved Means or Apparatus for Marking Lines on Blackboards
and other Surfaces.
1 JOHN ROBERT SPRATLING of 53 Springdale Road, Stoke Newington N.
Schoolmaster, do hereby declare the nature of this invention to be as follows:-
My invention relates to means or apparatus for facilitating the marking of paralell
lines and quadrilateral spaces upon blackboards and other surfaces for use in teaching
drawing, music, and writing in elementary schools, the kindergarten system etc.
The means or apparatus of this invention consists of a rectangular frame across
which a cord is stretched from side to side through perforations made in the side bars,
the free end of the cord being secured by winding on a stud or by a clamp or
otherwise.
To use the device the cords stretched across the frame are first chalked and the frame
then applied against the blackboard or other surface and the lines marked thereon by
pulling and then sharply releasing the cords in succession so as to leave an imprint of
the chalk thereon. A handle would be provided for holding the device in position when
in use.
For marking the lines of the musical staff a frame would be used across which a
cord is stretched five times from side to side at distances of say about half an inch
apart."
For marking lines for writing on, the cord would be stretched a suitable number of
times across the frame at distances of say one inch apart by means of which paralell
lines are obtained in the manner described, and to form squares for use in teaching
drawing etc. the frame would be turned half round so as to bring the cords across the
lines and enable lines to be struck at right angles to the first and thus form squares
for use in teaching drawing etc.
The device may also be used for marking lines and squares on paper for use in
reducing drawings by applying charcoal to the cords instead of chalk as before
described.
J. R. SPRATLING.
By A. M. & Wm. Clark,
53, Chancery Lane, London,
Patent Agents.

page_text: Improved Means or Apparatus for Marking Lines on Blackboards
and other Surfaces.
I, JOHN ROBERT SPRATLING of 53 Springdale Road Stoko Newington N.
Schoolmaster, do hereby declare the nature 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:-
My Invention relates to means or apparatus for facilitating the marking of parallel
regularly spaced and crossed lines upon blackboards and other surfaces, for the
purpose of teaching writing, music, needlework and drawing in elementary kinder-
garten and other schools. The means or apparatus of this invention consists of a light
frame having parallel cords tightly stretched across its face, which are first chalked
and then applied against the blackboard or other surface whereon the lines are caused
to be marked by pulling the cords away from, and allowing them to recoil sharply
against, the said surface, so as to leave an imprint of the chalk thereon. To form
crossed lines or squares for use in teaching drawing, etc; the operation would he
repeated, the frame being turned so as to bring the cords across the lines first formed
so that the second series of lines will be at right angles to the first. The device may
also be used for marking lines and squares on paper, for use in reducing drawings, in
which case charcoal would be applied to the cords instead of chalk. The number and
spacing of the cords would depend upon the intended purpose of the lines, and in
practice, a single cord carried to and fro a number of times across the frame, would
be used.
Reference is to be had to the accompanying drawings forming part of this specifica-
tion wherein figure 1 is a rear face view figure 2 a horizontal section; and figure 3
a vertical section (on line 1-1 figure 1) of the apparatus. Figures 4 and 5 show in
front face view and cross-section, part of the frame having an alternative mode of
holding the cord in position.
A is the rectangular or other frame and B is the blackboard (represented by broken
lines) on which the lines are to be marked. C is the cord threaded to and fro across
the frame and through corresponding holes a in the opposite side bars of the frame, in
the manner shewn, the holes passing through the frame from front to back, so that the
cord lies mostly on the front face of the frame so as to be in immediate contact with
the blackboard when the frame is applied thereto. The cord is in one continuous
piece and after being threaded through the holes and tightly distended is made fast at
both ends by means of pivoted clamps c. D is a cross bar or handle affixed to the
frame, by which to hold it up against the black board and serve as a stretcher to
maintain the sides against the tension of the cords.
As shewn in figure 1, the cords are spaced differently for different purposes, the
upper ones being represented as at distances suited for writing, the next lower ones
as at distances suited for producing squares or crossed lines for drawing purposes,

page_text: and the five lowest arranged for marking a musical staff. A sufficient number of
holes a are provided and a single continuous cord being used, it may be readily
threaded through holes at the required intervals.
In figures 4 and 5, the cord instead of passing through holes passes over the edge of
the frame and between outwardly projecting pairs of pins e fixed in the rebated outer
edge of the frame, so as to avoid injury to the hands etc, in using the frame.
Having now particularly described and ascertained the nature of the said invention
and in what manner the same is to be performed, I declare that what I claim is :—
The herein described apparatus for marking lines on blackboards and other surfaces,
consisting of a light frame having a cord or cords impregnated with dry coloring
matter, stretched across its face in parallel series at suitable regular intervals,
substantially as specified for use in the manner described.
Dated this 13th day of September 1887.
J. R. SPRATLING.
By A. M. & Wm. Clark,
53, Chancery Lane, London,
Patent Agents.