The SLATE AND STYLUS are tools used by blind persons to write text
that they can read without assistance. Invented by Charles Barbier
as the tool for writing night writing , the slate and stylus allow
for a quick, easy, convenient and constant method of making embossed
Braille character encoding . Prior methods of making
raised printing for the blind required a movable type printing press .
* 1 Design
* 2 Writing
* 3 History
* 4 Gallery
* 5 Notes
* 6 References
* 7 External links
The basic design of the slate consists of two pieces of metal,
plastic or wood fastened together with a hinge at one side.
The back part of the slate is solid with slight depressions spaced in
braille cells of six dots each. The depressions are approximately .75
mm (0.030 in) deep and about 1.5 mm (0.059 in) in diameter. The
horizontal and vertical spacing between dots within a cell is
approximately 2.5 mm (0.098 in), while the distance between adjacent
cells is about 4 mm (0.16 in).
The front of the slate consists of rectangular windows that fit over
the braille cells in the back. The inner rim of each window is
provided with six indentations, which assist the user to position the
stylus properly and press to form a dot.
There are pins or posts in the back of the slate positioned in
non-cell areas to hold the paper in place and keep the top properly
positioned over the back. The pins align with matching depressions on
the opposite side of the slate. A slate as designed for a normal 8.5
inch piece of paper has 28 cells in each row. The rows can be any
number, usually at least four.
The stylus is a short blunted awl with a handle to fit comfortably
the hand of the user.
Writing is accomplished by placing a piece of heavy paper in the
slate, aligning it correctly and closing the slate. The pins in the
back of the slate puncture or pinch the paper securely between the two
halves of the slate.
The person writing begins in the upper right, each combination of
dots in the cell has to be completed backward. The awl is positioned
and pressed to form a depression in the paper. The writer moves to one
of the other dots in the cell or to the next cell as appropriate.
The slate is repositioned as needed to continue writing on the paper.
When completed the writer removes the slate and turns the paper over
to read the braille by feeling the dots that were pushed up from the
Prior to the system devised by Louis Braille, a number of other
methods for blind people to read and/or write on paper were used. One
of the most popular was the English system of Dr. William Moon
invented in 1845. The English/Moon system or
Moon type is easy to
learn for the newly blind as it has a strong resemblance to the
familiar written alphabet, but
Braille has such great advantages over
the Moon system for regular usage that it quickly eclipsed the Moon
Braille with its slate and stylus was unique in that it was
the first and, until computers with screen readers , the only method a
blind person could write and read themselves what had been written.
The earliest systematic attempt to provide a method to "teach the
blind to read and to write, and give them books printed by themselves"
Valentin Haüy who used a system of embossed roman characters .
In June 1784, Haüy sought his first pupil at the church of
Saint-Germain-des-Prés . On 5 December 1786, Haüy's pupils had
embossed from movable letterpress type his "Essai sur l\'éducation
des aveugles " (Essay on the Education of Blind Children) the first
book ever published for the blind. Prior to 1786 tools for the blind
to read or write were the results of individuals personal approaches
to solutions. One of the more notable approach was that of Nicholas
Lucasian Professor of Mathematics at Cambridge ) blind
nearly from birth, devised an Arithmetical slate.
Braille evolved from the night writing of
Charles Barbier . "Ecriture
Nocturne" (night writing) was invented in response to Napoleon\'s
demand for a code that soldiers could use to communicate silently and
without light at night. Because it used a cell with 2 columns of six
dots each a total of 12 dots could be required for a single symbol,
the cell was too large for a single touch and was hard to read and
learn, it was not successful.
* ^ A B C Alpha Chi Omega (1908)
* ^ Shrady, et al.(1902)
* ^ Note: Different references assign invention of the slate and
stylus to either Barbier or Braille. However,
Braille (1829) credits
Barbier with the invention. Barbier's slate consisted of six slots;
Braille reduced it to three, as his cells were only half the size of
Barbier's. When dashes were removed , the slots were no longer needed
in full and were replaced with pairs of dots.
* ^ A B C D E F G Harry Houdini Collection (1888)
* ^ ADA (1994)
* ^ Note: The spacing for
Braille dots and cells are not consistent
throughout the world, See
Braille Cell Size Dimensions, Retrieved 18
February, 2017 for a chart of different standards.
* ^ Dodge (1920)
* ^ A B "ENGLISH/MOON" (web). Duxbury Systems , Inc. September
2006. Retrieved 2008-04-01.
* ^ Oregon Education Department (1897)
* ^ A B C Lowell, et al.(1893)
* ^ Stadelman(1913)
* ^ "What is Braille?" (web). American Foundation for the Blind.
* Alpha Chi Omega (1908). The Lyre of Alpha Chi Omega; Teaching the
blind. Original from the New York Public Library: Alpha Chi Omega. p.
Mary Mapes Dodge
Mary Mapes Dodge (1920). St. Nicholas; Chapter XI, the nine
gifts. Original from the University of Michigan: Scribner & Co. p.
* Perkins School for the Blind (1907). Report. Original from Harvard
University: Perkins School for the Blind. p. 69.
* Shrady; George Frederick Shrady; Thomas Lathrop Stedman; Joseph
Meredith Toner; et al. (1902). Medical Record. Original from Harvard
University: W. Wood. p. 621.
* Harry Houdini Collection (1888). The Popular Science Monthly;
Writing machines for the blind. Original from the New York Public
Library: D. Appleton. p. 645.
* Oregon Education Department (1897). Biennial Report. Original from
the New York Public Library: Oregon Education Department. p. 164.
* Mrs Frederick Rhinelander Jones (1893). "The Education of the
Blind". In Goodale, Frances. The Literature of Philanthropy. Harper &
Brothers. p. 187.
* Wisconsin State Board of Control (1904). Biennial Report. Original
from the University of Wisconsin - Madison: Wisconsin State Board of
Control,. p. 222.
* Stadelman, Joseph M. (1913). "Valentin Haüy". In Herbermann,
Catholic Encyclopedia . New York: Robert Appleton Company.
* Sauvage, G.M. (1913). "Louis Braille". In Herbermann, Charles.
Catholic Encyclopedia . New York: Robert Appleton Company.
* ADA (1994). Americans with Disabilities Act: Accessibility
Guidelines for Buildings. DIANE Publishing. p. 14. ISBN 0-7881-1830-7