BLIND, MECHANISM FOR THE. There are many ingenious mechanical contri vances for assisting in the instruction of the blind.
In the infancy of the art of teaching the blind, raised music was invented, in order that they might be enabled to acquire their lessons independent of a master. In 1827 the Society of Arts gave the large silver medal for a con trivance by Don Jaime Isern, the object of which is to enable a blind composer to transfer his thoughts to paper in the usual musical notation, without the necessity of employing an amanuensis. Embossed music, and maps and globes for teaching geography, would na turally be suggested to those persons who were engaged in teaching reading to the blind by raised figures. M. Weissembourg, a blind man of Mannheim, appears to have been the first person who made relief-maps ; up to which time the instruction given to the blind on geography was merely oral. Various methods for producing maps of this character were employed, but at first without success ; after a time, however, the chief difficulties were conquered, and a process which is minutely described by Dr. Guillie has supplied all the maps which have been in use at the Parisian Institution to the present time. The map of a country is pasted upon thick pasteboard, a wire is then bent round the curves of the coast, and along the courses of the rivers ; these wires are fastened down, and a second map in every respect similar to the first is pasted over it ; when this is pressed, the windings of the wire will be easily traced by the touch. Another plan consists in having a metal plate engraved with all the lines, ele vations, boundary marks, positions of towns, &c. ; from this plate impressions are struck in pasteboard, which produce a perfect em bossed map. There is art elementary treatise on mathematics, by the Rev. William Taylor, of York, called ' The Diagrams of Euclid's Elements of Geometry, arranged according to Simpson's edition, in an embossed or tangible form, for the use of blind persons who wish to enter upon the study of that noble science, York, 1828.
The intellectual education of the blind has made great advances within the last few years.
The interest connected with the question of Types for the Blind,' to which considerable impetus was given by the Society of Arts for Scotland at Edinburgh, who offered their gold medal for the best alphabet for the blind, has tended greatly to bring about this change. The late Mr. John Alston, the treasurer of the Glasgow Asylum, adopted the plain Roman characters deprived of their small extremities —the sans.serif of type-founders ; and, finding that it could be easily read, that it would also enable any seeing person who could read to be a teacher of the blind, he at once procured founts of type, and published several works in raised letters ; the success of these for their special object established the pre-eminence of his alphabet. He also brought out some beautiful embossed music and maps ; and he published the Old and New Testaments in 10 vols., super-royal 4to. The paper used for these works is strongly sized, to retain the impression. in order to account for the great extent of the Bible, it must be borne in mind that the paper can only be printed on one side, and that the letters require to be of consider able size in order to be distinct to the touch. The printing is effected by a copper-plate press. The types being strongly relieved, and liable frequently to give way under the heavy pressure required, it was necessary to have them re-cast four times during the progress of the work. The whole of the works have been completed within the walls of the Glas gow Asylum, a man and a boy acting as com positors, there being one pressman, and the ordinary teacher acting as corrector of the press.
The different kinds of industrial works exe cuted by the blind are nearly the same in all the asylums, varying slightly with the require ments of the district : at Glasgow they are house baskets of all kinds, mill baskets and hampers, door-mats, twines, mattresses, hair friction gloves, curled hair for upholsterers, hearth and door rugs, table rugs, fringed rugs, articles of needle-work, stockings and pan soufles, nets, sacks and sacking.