B L I 



608 



B L I 



Blind. directly down, or towards the body of the calcula- 

 -~V ' tor. Nine is expressed by a peg of the third set 

 (with a square head) when its edges are divided to 

 right and left ; and the same peg expresses the cy- 

 pher, when its edges are directed up and down. 

 When it is necessary to express a vulgar fraction, 

 I place the numerator in the groove immediately 

 above, and the denominator in that immediately be- 

 low the groove in which the integers stand ; and in 

 decimal arithmetic, an empty hole in the integer 

 groove represents the comma or decimal point. By 

 similar breaks, 1 also denote pounds, shillings, pence, 

 &c. ; and by the same expedient, I separate, in divi- 

 sion, the divisor and quotient from the dividend. 

 Coefficients and indices, in algebra and fluxions, are 

 supplied upon similar principles." 



Various attempts have been made to supply the 

 blind with tangible musical characters, or signs, by 

 which their progress in the acquisition of an art 

 which affords them so^reat delight, and for which 

 they are so peculiarly qualified, might be materially 

 facilitated. We do not think, however, that these 

 attempts have been attended with the same success, 

 as in the case of the palpable arithmetic. In Tan- 

 sure's Musical Grammar, p. 93., it is recommended, 

 that the blind musician should be provided with a 

 smooth board with ledges of deal glued on it at pro- 

 per distances, to repres -nt the five lines of the musi- 

 cal staff; with such additional lines as occasion may 

 require. In these ledges, as well as in the intervals 

 between them, a number of holes are to be drilled 

 for the reception of a variety of pegs of different 

 forms, intended to indicate the various kinds of notes 

 in music ; such as semibreves, minims, crotchets ; 

 together with the rests, flats, sharps, bars, &c. 



In a contrivance of Mr Cheese for the same pur- 

 pose, and winch we have seen actually introduced into 

 some asylums of the blind, a stuffed cushion is sub- 

 stituted for the board of Tansure, upon which strings 

 are sewed to represent the musical staff, and the pegs 

 intended to denote the various musical characters, are 

 fixed upon sharp pointed wires, by which means they 

 may be stuck into any required part of the cushion. 

 What we chiefly object to this contrivance, is the 

 multiplicity of pegs, of awkward and arbitrary forms, 

 which it employs, the ready use of which cannot be 

 taught to the blind without a great deal of trouble. 

 Instead of this, we think it would be better to have 

 the heads of the pegs formed into a resemblance of 

 the notes, rests, bars, shakes, &c. which are actually 

 employed in written music, which are sufficiently 

 simple and intelligible, and far from being too nume- 

 rous, as they have a relative value from their position, 

 as well as an absolute one from their form. 



In the year 1786, an Essay on the Education of the 

 Blind was printed at Paris, under the patronage of 

 the Academy of Sciences. It is the composition of 

 M. Haiiy, and does great honour to the author, on ac- 

 count of the comprehensive and liberal views which it 

 exhibited. It contains a detail of a great variety of 

 expedients by which the blind may be successfully in- 

 structed in many of the mechanic arts, as well as in 

 music, arithmetic, geography, &c. and may even 

 be taught to read, write, and print. In order to in- 



struct the blind in music, at the institution of which 

 M. Haiiy communicates the details in this work, mu- 

 sical characters of every necessary form were cast in , 

 metal, and so many in number as to represent upon 

 paper, by elevations on its surface, all the possible 

 varieties that occur. In teaching geography, which 

 was the department of M. Weissenbourg and Mad. 

 Paradis, the circumference of countries was marked 

 out by a tenacious and viscid matter, and the different 

 parts of the maps was covered with a kind of sand, 

 mixed with glass in various modes ; the order of the 

 towns being distinguished by grains of glass of a 

 greater or less size ; or, according to the plan of M. 

 Haiiy, the limits of the maps, for the use of the blind, 

 were marked by a small rounded iron wire ; and by 

 some difference, either in the form or size of every 

 part of a map, the pupils were assisted in distinguish - 

 jng one part from another. 



The manner in which the blind are taught to write 

 and print, is as follows : The pupil, by repeated ex- 

 periments, having familiarised himself to the forms of 

 the letters as drawn in relief, both in their direct and 

 inverted position, gradually learns to impress them 

 upon strong paper, a little moistened, with the point 

 of a blunt iron pen or stylus, which marks without 

 piercing the paper. By this means the letters become 

 perceptible to the touch, on the one side sunk, and on 

 the other in relievo ; and thus the blind may be ena- 

 bled to form and decipher, not only the' characters 

 required in common language, but also mathematical 

 diagrams, geographical plans, and all the characters 

 employed in arithmetic, music, &c. In printing, the 

 blind compositor has a box for every letter, on the 

 outside of which is marked in relief, the peculiar cha- 

 racter belonging to each. By this means he is enabled 

 readily to choose and arrange his types, and when they 

 are set, he makes use of a strong paper, slightly mois- 

 tened, like that employed in writing, in order to ren- 

 der it more easily susceptible of impressions. Having 

 laid this upon his types, by the operation of the press, 

 or the strokes of a small hammer, he raises an impres- 

 sion upon the paper, which, when dry, is sufficiently 

 obvious to the touch, to enable the blind to read by 

 their fingers, and is so durable as to be by no means 

 easily effaced. This method of printing, it is evident, 

 is also legible by the eye-sight ; and it has one advan- 

 tage over that in common use, that the types are set, 

 not in the reverse, but in the direct order, so that 

 the characters may appear in relievo, in the same or- 

 der, on the opposite side of the paper. Dr Biack- 

 lock mentions, that he was in possession of a copy of 

 M. Haliy's Essay, which was printed in the manner 

 now described, and also bound by the blind pupils of 

 the Parisian institution, with great neatness. An 

 English translation of the Essay is annexed to the 

 edition of that gentleman's poems, printed at Edin- 

 burgh in 4to, in 1793. 



See Journal des Scavans, Nov. 19th 1685, which 

 contains James Bernoulli's method of teaching ma- 

 thematics to the blind, (m) 



BLISTER. See Farriery, Pharmacy, and 

 Surgery. 



BLITUM, a genus of plants of the class Monan- 

 dria, and order Digynia. See Botany, (w) 



Blind 



II 

 Blitum. 



