Visible speech, the science of universal alphabets, : or Self-interpreting physiological letters, for the writing of all languages in one alphabet ; illustrated by tables, diagrams, and examples
Alexander Melville Bell's 1867 treatise on Visible Speech, published in London and New York, set out a physiological alphabet meant to write every language for phoneticians, teachers of the deaf, and philologists. Line diagrams show the mouth, tongue, palate and nasal passage in cutaway profile, with dotted airflow arrows and rows of curved symbol glyphs usable as anatomical schematics or abstract mark-making.
