Page:Popular Science Monthly Volume 33.djvu/664

646 upon the other side (verso) in the interlinear spaces. This system vastly increases the capacity of the sheet of paper. There are also pocket tablets, or replets, of which different models are represented in the engraving; they are for the most part strips of undulated zinc, to which are hinged guides bearing several rows of openings.

Signora della Casa, an Italian woman, constructed the apparatus represented in the first figure of our engraving (Fig. 2). A

 1 Signora della Casa's piston-guide. 2. Recto-verso tablet of Laas d'Aguen. 3. Goldberg's Danish tablet. 4. English reglet. 5. Ballu's reglet. 6. Austrian tablet. 7. Braille's tablet. 8. Beaufort's stylograph.

little carriage bearing six buttons, which control as many movable pins, glides along a ruler that is notched at equidistant intervals. When one of the buttons is struck with the finger, the corresponding pin springs out and makes a point on the paper. A spring brings the pin back, and after the writing of each sign, the carriage is slid on a notch along the guide. But this apparatus is not in use, and we mention it only as a curiosity.

When we wish to write to a blind man by the Braille alphabet, we can accustom ourselves to reverse the signs by copying them as they look in a mirror; or we can use a table composed by M. Merricant, of Toulouse, which gives the characters written both ways; or we can learn only the reversed alphabet, and read the writing, if we have occasion to read it, on the hollowed or reverse side of the sheet, or the side on which it is written, which, with the eyes, will be easy enough.

For the use of blind in writing to seeing people, designs have