602 



BLIND. 



Blind. charitable contribution ; but instructed in a variety 

 "~ v ' (( f trades, such as weaving, spinning, rope-twisting, 

 &c, which it is found they can exercise in great ) 

 fection ; and where also the cultivation of their mo- 

 ral and intellectual faculties is properly attended to. 



It is not very long ago since the prejudice against 

 the capacity of the blind was so great, that a de- 

 scendant of the celebrated Lord Verulam, Mr Nicho- 

 las Bacon, who had the misfortune to lose his eye- 

 sight at nine years of age, and afterwards assiduously 

 addicted himself to study, found great difficulty in 

 procuring admission into the learned seminaries of 

 Brabant, where he resided. This prejudice, how- 

 ever, lie so completely overcame, that he was after- 

 wards created doctor of laws in the city of Brussels, 

 with high approbation ; and having commenced plead- 

 ing counsellor, or advocate in the council of Brabant, 

 he had the pleasure of terminating almost every suit 

 in which he was engaged, to the satisfaction of his 

 clients. It may, nevertheless, be doubted, whether 

 the profession of a barrister affords a sufficiently pro- 

 mising opening for the abilities of a blind man, to 

 induce him to devote himself to such a pursuit. 



We read also of a celebrated blind sculptor in the 

 Cours de Peint of De Piles, who took the likeness 

 of the Duke de Bracciano in a dark cellar, by means 

 of moulding his face in wax ; and who made a mar- 

 ble statue of King Charles I., with great elegance 

 and justness: yet we would not from all this infer, 

 that the blind are well qualified to excel in sculpture. 

 A sufficient variety of liberal pursuits, however, will 

 still remain within their reach, in the various depart- 

 ments of natural philosophy, mathematics, chemistry, 

 theology, and the belles lettres ; in all of which we 

 have seen that they are well qualified to excel : and 

 in the fine art of music, their eminence has been un- 

 rivalled. 



A variety of expedients have been devised for fa- 

 cilitating the studies of the blind, and rendering that 

 readily intelligible to the touch, which, in those who 

 see, is addressed only to the eye-sight. It is well 

 known, that the celebrated Saunderson had contrived 

 for himself a machine, by which he greatly facili- 

 tated his arithmetical calculations, as well as his geo- 

 metrical studies. Of this kind of palpable arith- 

 metic, he has himself given an account ; and it is 

 much more minutely described in Diderot's Letters 

 on the Blind, already mentioned. It consisted of a 

 square board of a convenient size, divided by paral- 

 lel lines into a considerable number of smaller squares. 

 Each of these smaller squares, or separate depart- 

 ments, wa6 pierced with nine holes, standing in three 

 parallel rows ; and by fixing a pin in one or other of 

 these nine holes, the nine digits were denoted, ac- 

 cording to the position of the pin. In order to faci- 

 litate his calculation, Saunderson made use of two 

 sizes of pins, a larger and a smaller. The pins with 

 large heads were always placed in the centre holes of 

 the squares ; and when they stood alone, without 

 any small pins, they denoted the cypher. The num- 

 ber 1 was denoted by a pin with a small head, placed 

 in the centre of a square ; the number 2, by a large 

 pin in the centre, and a small one at the side, in the 

 hole which was first in order ; the number 3, by a 

 large pin in the centre, and a small one in the 6econd 



hole at the side ; and so on in order, to the number 

 9. By this means, it is evident that any sum could v 

 be expressed, in a number of squares corresponding 

 to the number of its figures ; and thus, all the arith- 

 metical operations performed. Saunderson, it is said, 

 (1 wonderful facility in the use of this ma- 

 and was accustomed also, by means of it, to 

 form diagrams for his geometrical demonstrations ; 

 the pins serving the purpose of making the angles of 

 the figures, either alone, or with silk threads stretched 

 between them. 



An arithmetical machine was also contrived by- 

 Mr Grenville, who had lost his eye-sight, consisting 

 of a square board full of holes, and ten sets of pegs 

 of diflercnt forms, corresponding to the nine digits 

 and cypher. But by far the most simple and com- 

 modious of these machines, seems to be that invented 

 by Dr Henry Moyes for his own use ; of which he 

 has himself inserted an account in the Ency.l. Brit. 

 3d. edit. He informs us, that when he began to 

 study the principles of arithmetic, he soon found 

 that a person deprived of sight could scarcely pro- 

 ceed in that useful science, without the aid of pal- 

 pable symbols representing the ten numerical charac- 

 ters ; and being then unacquainted with Saunderson's 

 in -t hod, he embraced the obvious, though, as he 

 afterwards found, imperfect expedient, of cutting 

 into the form of the numerical characters, thin pieces 

 of wood or metal ; which being arranged on the 

 surface of a board by means of a lamina of wax, 

 readily represented any given number. It soon, 

 however, occurred to him, that his notation, consist- 

 ing of ten species of symbols or characters, was much 

 more complicated than was absolutely necessaiy ; and 

 that any given number might be distinctly expressed 

 by three species of pegs alone, viz. two with heads 

 of the form of a right-angled triangle, and distin- 

 guished from each other by having a notch cut in 

 the oblique side or hypothenuse of one of them, their 

 other two sides being, one of them a continuation of 

 the peg, and the other at right angles to it ; and 

 the third peg having a head of the form of a square. 

 These pegs were to be stuck into a board of about 

 a foot square, and divided into 576 little squares, by 

 lines which were cut a little into the wood, so as to 

 form a superficial groove. At each angle or inter- 

 section of the grooves, a hole was made for the in- 

 sertion of the pegs. Sixty or seventy of each kind 

 of pegs were necessary, which were placed in a case 

 consisting of three boxes or cells, one for each set. 



" Things being thus prepared," says the Doctor, 

 " let a peg of the first set (with a plain triangular 

 head) be fixed into the board ; and it will acquire 

 four different values, according to its position re- 

 specting the calculator. When its sloping side is 

 turned towards the left, it denotes one, or the first 

 digit ; when turned upwards, or from the calculator, 

 it denotes two, or the second digit ; when turned to 

 the right, it represents three ; and when turned down- 

 wards, or towards the calculator, it denotes four, or 

 the fourth digit. Five is denoted by a peg of the 

 second set (with a notched triangular head), having 

 its sloping side, or hypothenuse, turned to the left ; 

 six, by the same turned upwards ; seven, by the same 

 turned to the right j and eight, by the same turned 



Blind. 



