Almost everyone knows that Braille is a system of raised dots which can be read by touch, but have you ever thought about how this system actually works?

A little about Louis Braille

Louis Braille was born in a small French town in 1809. He was the son of a leatherworker, and when he was three he was playing with his father’s tools, when he slipped and injured one eye. The injury became infected, and the sight in that eye was lost. Tragically, the infection then spread to the other, healthy eye, leaving Louis totally blind.¹

Louis was a bright boy, and with support from his family and neighbours, was actually able to attend the local school for a few years. As a result of this, he was able to win a scholarship at France’s only school for the blind, the Institution Royale des Juenes Aveugles (Royal Institute for Blind Youth).

Most of the teaching at the school was done by speech and memory, but the pupils were taught to read. By a lengthy, laborious and specialised process, books with raised letters were produced, first by creating the shapes of indivdual letters out of wire, and then by forcing these letters into the wrong side of a piece of paper so that the shape was pushed through. This allowed the pupils to read, but they still could not write.

Louis and his fellow pupils were introduced to a system called ‘night-writing’ which had been developed for the military. It used a code of dots and dashes pushed through the surface of the paper. The idea had been that soldiers could read messages in the dark, without showing a light to the enemy. But it was a phonetic system, with numerous strokes, and proved too complex for both the soldiers and the blind pupils: it was abandoned.

Louis, however, was inspired, and worked on a new version, with less strokes and a more rational, systematic methodology: Braille. This would have been an extraordinary achievement for anyone. What is astounding is that Louis had laid out the fundamentals of his system by the age of fifteen.

Louis’ system, which he adapted and improved during the rest of his life, abandoned dashes and stuck rigidly to a system of dots which can only be placed in one of the six spaces within a Braille cell. This means that there are no ascenders and descenders to Braille character (such as the tails on printed letters like p, h, l, b, d f). This makes it very easy for a blind reader to ‘find’ and explore the whole of the character. The rigid layout also makes it easy for a blind person to write, as well as read Braille: a basic Braille frame for writing by hand includes a sort of stencil with hole made up of the outline of the Braille character - the blind person can easily position a stylus within this frame top, middle, bottom, left, right, as appropriate, to push through each dot in turn.

The Braille Alphabet

Many people assume that the dots will be arranged so that the Braille letters will look like the letters of the alphabet, but this is not the case:

Louis realised that there was no need for Braille to mimic the sighted alphabet, although he did keep to the traditional alphabet, rather than a phonetic system, to make Braille easy to transcribe. Instead, Louis laid the basis for a communication system that would minimise confusion for the blind reader, and would maximise the opportunities that such a system could offer.

In Braille, each dot has a number:

The teenage Louis made the remarkable decision to use these numbers and create a mathematical basis for Braille. Using the dot numbering system, this is how the alphabet translates:

A = 1

B = 1 2

C = 1 4

D = 1 4 5

E = 1 5

F = 1 2 4

G = 1 2 4 5

H = 1 2 5

I = 2 4

J = 2 4 5

K = 1 3

L = 1 2 3

M = 1 3 4

N = 1 3 4 5

O = 1 3 5

P = 1 2 3 4

Q = 1 2 3 4 5

R = 1 2 3 5

S = 2 3 4

T = 2 3 4 5

U = 1 3 6

V = 1 2 3 6

W = 2 4 5 6

X = 1 3 4 6

Y = 1 3 4 5 6

Z = 1 3 5 6

It is immediately obvious that Louis is following a specific progression of some of the sixty-three possible combination of his six dots.² However, Louis is not following a purely mathematical progression, but also taking into account some criteria:

• Only the letter A is made up of a single dot. More letters made of single dots could cause confusion for a blind reader.
• Every combination used for a letter symbol contains one of the 'top row' dots: 1 and 4. In Braille terminology all the letters are therefore known as 'upper signs'. This means that the blind reader has a point of reference, they can always find the top of each letter, and cannot mistake one letter for another.

You might think that after allocating 26 symbols for the letters of the alphabet, his next move would be to allocate ten symbols for the numerals, but no. In the first place that were not sufficient 'upper signs' left for the numerals, so any long number, made of 'lower signs' could become confusing. Plus, Louis realised that he must use his sixty-three possible dot combinations wisely, if he was to get maximum practicality out of his system. So Louis created just one new symbol,

Thus this is the letter d:

You might at first think that letters and numbers are all Braille needs, and indeed these symbols are the basis of what is known as "Grade 1 Braille". Any basic information can be communicated using Grade 1 Braille, so it is used on simple signs and for people who may benefit from a simple system - such as children or elderly people who have lost their sight late in life. But, there are two very good reasons for extending the system:

• More complicated writing: including quotations, acronyms, and mathemtical and finanical calculations require more sophisticated options

Grade 1 Braille is very

cumbersome. The average

Braille system for

writing by hand provides

only 25 characters per

line across a sheet of

paper about the width of

foolscap or A4. This

paragraph demonstrates

just how cumbersome that

is - it would take nearly

up a whole page written

out in Grade 1 Braille.