The blind are those who want, or are deficient in, the sense of sight. Blindness may vary in degree from the slightest impairment of vision to total loss of sight; it may also be temporary or permanent. It is caused by defect, disease, or injury to the eye, to the optic nerve, or to that part of the brain connected with it. Old age is sometimes accompanied with blindness, occasioned by the drying up of the humours of the eye, or by the opacity of the cornea, the crystalline lens, etc. The blind are often distinguished for a remarkable mental activity, and a wonderful development of the intellectual powers. Their touch and hearing, particularly, become very acute.
As early as 1260 an asylum for the blind (L'hospice des Quinze-Vingts) was founded in Paris by St Louis for the relief of the Crusaders who lost their sight in Egypt and Syria; but the first institution for the instruction of the blind was the idea of Valentin Hauy, brother of the celebrated mineralogist. In 1784 he opened an institution in which the blind were instructed not only in appropriate mechanical employments, as spinning, knitting, making ropes or fringes, and working in paste-board, but also in music, in reading, writing, ciphering, geography, and the sciences. For instruction in reading he procured raised letters of metal; for writing he used particular writing-cases, in which a frame, with wires to separate the lines, could be fastened upon the paper; for ciphering there were movable figures of metal, and ciphering-boards in which the figures could be fixed; for teaching geographymaps were prepared upon which mountains, rivers, cities, and the boundaries of countries were indicated to the sense of touch in various ways, etc.
Similar institutions were soon afterwards founded in Amsterdam, Berlin, Brussels, Copenhagen, Dresden, Edinburgh, Liverpool, London, Vienna, and in many towns of the United States. By 1900 there were comparatively few large cities that did not possess a school or institution of some kind for the blind.
At the start of the 20th century the attitude towards the blind was rather patronising, and one source may be quoted as saying 'the occupations in which the blind are found capable of engaging are such as the making of baskets and other kinds of wicker-work, brushmaking, rope and twine making, the making of mats and matting, knitting, netting, fancy work of various kinds, cutting fire-wood, the sewing of sacks and bags; the carving of articles in wood, etc'. However, it was also recognised that more skilled tasks could also be performed by blind persons, and the same source notes that 'Piano-tuning is also successfully carried on by some, and the cleaning of clocks and watches has even been occasionally practised by them'.
Around 1900 an impetus was given, in Britain, to the higher education of the blind by the formation of the British and Foreign Blind Association, the establishment of a college for the Blind Sons of Gentlemen at Worcester, and the Royal Normal College and Academy of Music for the Blind, Upper Norwood.
Various systems were devised for the purpose of teaching the blind to read, some of which consisted in the use of the ordinary Roman alphabet, with more or less modification, and some of which employ types quite arbitrary in form. In all systems the characters rise above the surface of the paper so as to be felt by the fingers. The type adopted by Hauy was the script or italic form of the Roman letter. This was introduced into England by Sir C. Lowther, who printed the Gospel of St. Matthew in 1832 with type obtained from Paris. Before this Gall of Edinburgh made use of an embossed alphabet based on the ordinary Roman small letters, in which all curves were replaced by angular lines, and in 1834 he published the Gospel of St John in this character. Subsequently he introduced various improvements, and in particular the letters were produced with serrated surfaces, thus giving greater distinctness. Alston of Glasgow, Howe of Boston, and others also used the Roman form; but the former (who was the first to print the whole Bible, in 1840) adopted the Roman capitals, while the latter adopted the small letters, printing in this type the Bible and many other books. Of alphabets deviating entirely or nearly so from the Roman letter, one consists of a stenographic shorthand invented by Lucas of Bristol; another was a phonetic shorthand devised by Frere of London. In Dr. Moon's alphabet some of the characters are Roman, others are based on or suggested by the Roman characters. The Braille system, widely adopted by the laye 20th century, is one in which the letters are formed by a combination of dots. Dr. Moon's system from its simplicity and the size of its characters is in very general use in books for the blind. There are also systems by which the blind are enabled to write, and the writing may be either in relief so as to be read by the blind, or in characters that may be read by those who see. Research Blind
A bobbin is a reel or other similar contrivance for holding thread. It is often a cylindrical piece of wood or plastic with a head, on which thread is wound for making lace; or a spool with a head at one or both ends, intended to have thread or yarn wound on it, and used in spinning machinery (when it is slipped on a spindle and revolves therewith) and in sewing-machines (applied within the shuttle). Research Bobbin
Cotton-spinning is a term employed to describe in the aggregate all the operations involved in transforming raw cotton into yarn. The word 'spinning' has also a more limited signification, being used to denote the concluding process of the series. The following affords a general notion of the nature and order of the successive operations carried on in the manufacture of cottonyarn:
(1) Mixing, the blending of different varieties of raw cotton, in order to secure economical production, uniform quality and colour, and an even thread in any desired degree.
(2) Cleaning, an operation partly effected in mixing, partly by scutching, the cotton being prepared in the form of a continuous lap or rolled sheet for the next process.
(3) Carding, an operation in which the material is treated in its individual fibres, which are taken from the lap, further cleansed, and laid in a position approximately parallel to each other, forming a thin film, which is afterwards condensed into a sliver - a round, untwisted strand of cotton.
(4) Drawing, the drawing out of several slivers to the dimensions of one, so as to render the new sliver more uniform in thickness, and to place the fibres more perfectly in parallel order.
(5) Stubbing, the further drawing or attenuation of the sliver, and slightly twisting it in order to preserve its cohesion and rounded form.
(6) Intermediate or second stubbing, a repetition of the former operation and further attenuation, not necessary in the production of coarse yarns.
(7) Having, a continuation of the preceding, its principal object being to still further attenuate the sliver, and give it a slight additional twist.
(8) Spinning, which completes the extension and twisting of the yarn. This is accomplished either with the throstle or the mule. By means of the former machine the yarn receives a hard twist, which renders it tough and strong. By means of the latter yarns of less strength are produced, such as warps of light fabrics and wefts of all kind.
Up to the middle of the 18th century the only method of spinning known was that by the hand-wheel, or the still more primitive distaff and spindle. In 1767 a poor weaver of the name of Hargreaves, residing at Stanhill, near Blackburn, in Lancashire, invented a machine for spinningcotton, which he named a spinning-jenny. It consisted at first of eight spindles, turned by a horizontal wheel, but was afterwards greatly extended and improved, so as to have the vertical substituted for the horizontal wheel, and give motion to from fifty to eighty spindles. In 1769 Arkwright, originally a barber's apprentice, took out a patent for spinning by rollers. From the circumstances of the mill erected by Arkwright at Cromford, in Derbyshire, being driven by water-power, his machine received the name of the water-frame, and the thread spun on it that of water-twist. The next important invention in cotton-spinning was that of the mule, introduced by Samuel Crompton, of Bolton, in 1775, and so called from its combining the principle of the spinning-jenny of Hargreaves with the roller-spinning of Arkwright.
Numerous improvements in cotton-spinning have been subsequently introduced up to the present day, but they are all, more or less, modifications of Arkwright's spinning-frame and Crompton's mule-jenny. Among the principal of these may be mentioned the throstle, an extension and simplification of the original spinning-frame, introduced about the year 1810. Research Cotton-Spinning
Cotton-wool is the term used for cotton when used in the open form, without being spun or woven. It is usually composed of short fibres which are no use for spinning, and is used in medicine for applying antiseptic material and for removing make-up and for wadding and stuffing. Research Cotton-wool
Dyeing is the art of giving colour to textile and other articles in such a way that the colours are more or less permanent, and not readily affected by the action of light, washing, etc. Like spinning and weaving it was originally a home industry, as it still is in many places. Until about 1850 natural dye-stuffs alone were employed, but the discovery of dyes of all colours that can be obtained from coal-tar products revolutionized dyeing as an industry, and the vegetable dye-stuffs were gradually superseded by the newer colours.
Before dyeing, the materials have generally to be cleansed or bleached to get rid of undesirable colouring matters or impurities; and frequently a textile material is subjected to some subsidiary treatment in order to obtain special effects. For example, cottonyarn may be subjected to the action of strong causticsoda ('mercerizing' process) while in a state of great tension, in order to give it a permanent silky lustre.
Dyeing is not only an art, it is also a branch of applied chemistry. One fundamental principle is, that the colouring matter and other necessary substances must be applied in a state of solution, and while in direct contact with the fibre they must be rendered insoluble, so that they are precipitated within or upon the fibre and thus permanently fixed. The method of effecting this varies greatly according to the fibre and the colouring matter employed. As a rule the vegetable and the animal fibres are dyed by very different methods. The affinity of the animal fibres for certain colouring matters is often so great that they are readily dyed by simple immersion in hot colour solutions;
but this simple process is not generally sufficient. According to the method of their application in dyeing the following groups: of dye-stuffs may be distinguished: Avid Colours, Basic Colours, Direct Colours, Developed Colours, Mordant Colours, Miscellaneous Colours, Reactive Colours.
The acid colours are so called because they are of an acid character and are applied in an acid dye-bath. As a rule, they are only suitable for dyeing the animal fibres, e.g. wool and silk, also leather, horn, feathers, etc. Only a few vegetable dye-stuffs belong to this class, for example, the purple colour orchil and the blue colour indigo extract. On the other hand, the acid colours derived from coal-tar - and increasingly petroleum - are very numerous and yield a great variety of hues - red, orange, yellow, green, blue, violet, brown, and black, each with its particular name.
The basic colours are so called because their essential constituents, to which they owe their dyeing power, are organicbases. The bases themselves are colourless and too insoluble in water to be of use, hence they are employed in the form of their soluble coloured salts, usually the hydrochlorides of the colour-bases. Their solutions are precipitated by tannic acid, because it combines with the colour-bases to form insoluble tannates. Wool, silk, and animal substances generally have a direct attraction for colour-bases, and hence these fibres are readily dyed by simple immersion in hot aqueous solutions of the basic colours. Cotton and linen, on the other hand, are not dyed so readily; they need first to be prepared or impregnated with tannic acid, and thus prepared are said to be mordanted, the tannic acid in this connection being styled the mordant. Most of the colours of this class are fugitive to light, and all but one, barberryroot, are derived from coal-tar products.
The direct colours are so called because they dyecotton direct, that is, without the aid of any mordanting process. The first of this class derived from coal-tar was congo red, discovered in 1884; this group includes a very great variety of fast colours, and forms, indeed, one of the most important and valuable series of dye-stuffs employed. Cotton, linen, and the vegetable fibres generally are dyed in the simplest possible manner by merely boiling them in a solution of the dye-stuff, with or without the addition of a little soap, carbonate or sulphate of soda, etc. Wool and silk are frequently dyed in the same manner as cotton. Very few vegetable dye-stuffs belong to the direct colours, e.g. Safflower, Turmeric, Saffron, Annatto. They are all fugitive, and have been of little or no importance to the dyer since the end of the 19th century. The coal-tar colours of this class, on the other hand, are extremely numerous.
The developed colours include a variety of colours which are formed in situ upon the fibre by the successive application of two or more substances. These colours are all of coal-tar origin. A number of them belong to the so-called azo colours, derived from compounds containing nitrogen.
The mordant colours form one of the most important classes of colouring matters, for they include not only most of the vegetable dye-stuffs, e.g. madder, logwood, fustic, etc, but also many valuable fast coal-tar colours, commonly known as the alizarin colours, after their typical representative, alizarin. These mordant colours have by themselves very little colouring power, as a rule, and if employed alone in dyeing give little or no result. If applied, however, in conjunction with metallic salts, notably those of chromium, aluminium, iron, tin, and copper, they each yield a variety of colours, according to the metallic salt employed. In employing them usually two distinct operations are involved: first, that of applying the metallic salt or mordant, called the mordanting process ; and second, that of dyeing proper, in which the mordanted material is boiled in a solution or decoction of the dye-stuff. During the dyeing operation the colouring principle of the dye-stuff combines with the metallic salt already upon the material, and the colour is thus produced and fixed upon the fibre. The method of mordanting varies with the fibre and the metallic salt employed. The vegetable dye-stuffs of this class include Madder, Sapanwood, Camwood, Barwood, Old Fustic, Young Fustic, Quercitron Bark, Persian Berries, Weld, Logwood. Madder was formerly the most important and highly valued of the dye-stuffs of this class, being especially employed to produce the fine 'Turkey-red' dye; but was entirely superseded by the coal-tar colour alizarin towards the end of the 19th century.
Reactive colours combine directly with the fibre being dyed through a chemical reaction and result in a fast colour. The first ranges of reactive dyes for cellulose fibres were introduced in the mid-1950s.
Similarly, the employment of cochineal (an insect dye) has also greatly diminished through the introduction of the cheaper colours. Camwood and barwood are almost entirely used in wool-dyeing, either in conjunction with the indigo-vat or for the purpose of dyeing various shades of brown. Old fustic is the most important of the yellow mordant dye-stuffs, and the colours are fast although not very brilliant. Young fustic yields fugitive colours, and has been little used since 1900. Quercitron bark is an excellent dye-stuff employed by wool-dyers for the production of bright orange and yellow colours. Persian berries and weld, a species of wild mignonette, are both excellent dye-stuffs, but their employment is now limited. Logwood is largely employed by wool, silk, and cotton dyers for dyeing black and dark-blues, which, although fast to washing, are only moderately so towards light. During the 20th century dyewoods were gradually replaced by coal-tar colours.
Among miscellaneous colours are several dye-stuffs applied in a distinct manner. Indigo is a dark-blue powder quite insoluble in water, but can be rendered soluble for dyeing purposes by two methods. The first method converts the indigo into so-called indigo extract, which is sold as a blue paste and applied as an acid colour in dyeing wool and silk. In the second method the indigo-blue is converted into indigo-white, which readily dissolves in the alkalipresent, the solution thus obtained being called an indigo-vat. If cotton, wool, or silk is steeped for some time in the clear yellow solution of such a vat, and then exposed to the oxidizing influence of the air, they are dyed a permanent blue. The indigo-white absorbed by the fibre loses its acquired hydrogen, and thus insoluble indigo-blue is regenerated within and upon the fibre. Aniline black is a valuable colour, produced direct upon the fibre by the oxidation of aniline, and remarkable for its extreme permanency.
Catechu is a vegetable dye-stuff used in dyeing cotton and woollen brown. On wool, catechu yields khaki browns in single bath by using copper sulphate as the mordant. On silk it is largely employed for weighting purposes in the process of dyeing black. Chrome Yellow, Iron Buff, Prussian Blue, and Manganese Brown, employed in cotton dyeing, are frequently classed as mineral colours. Chrome yellow is obtained by immersing cotton successively in solutions of acetate of lead and bichromate of potash, whereby the yellow precipitate of chromate of lead is fixed upon the fibre. Iron buff is obtained in a similar manner by the successive application of iron sulphate and carbonate of soda, and finally developing the full colour by washing with water and exposure to air. The buff colour is really due to the precipitation of oxide of iron on the cotton. Prussian blue is at once developed by passing the buff-dyed cotton through an acidified solution of potassium ferrocyanide. The production of manganese brown on cotton is similar to that of iron buff. The brown colour ultimately produced upon the fibre is an oxide of manganese. The mineral colours are very useful for certain purposes, and are to be regarded as very fast to light. Research Dyeing
A throstle was a drawing-frame machine used in the manufacture of cotton, succeeding the spinning-jenny in around 1885. The throstle was used for attenuating slivers of fibre by passing them through consecutive pairs of rollers, each pair in the succession revolving at a higher speed than its predecessor. The specific difference between the action of the throstle and the mule was that the throstle had a continuous action, drawing, twisting and winding; while the mule had an alternative action, drawing and twisting and then winding. Research Throstle
Acantholyda is a genus of web-spinning sawfly of the family Pamphillidae. Acantholyda erythrocephala is widespread in Europe, and has been introduced to the USA. It lives mostly in young pine forests where the larvae develop feeding on pineneedles, and the adults fly from late April to May. Research Acantholyda
Cephalcia is a genus of Web-spinning sawfly of the family Pamphillidae. Cephalcia abietis is widespread over most of the temperate part of Eurasia, living in older strands of spruce in the foothills and mountains. The larvae live communally in brownish silkensacs which they spin on branches of the host tree, falling to the ground and burrowing at the end of summer, resting in its underground chamber for up to three years before pupating. The adults fly from the middle of April to the end of June. Research Cephalcia
Flax or linseed is a popular name of plants of the genusLinum, family Linaceae of which there are roughly 100 species. They are herbs or small shrubs with narrow leaves and yellow, blue or white flowers arranged in variously formed cymes. They occur in warm and temperate regions over the world. The cultivated species is Linum usitatissimum. The fibre which is used for making thread, and cloth called linen, cambric, lawn, lace, etc, consists of the woody bundles of the slender stalks. The fine fibres may be so separated as to be spun-into threads as fine as silk. A most useful oil is expressed from the seeds, and the residue, called linseed-cake, is one of the most fattening kinds of food for cattle. When the plant is ripe it is pulled up by the roots, tied together in little bundles, and usually left upright on the field until it becomes dry, when the seeds are separated, either by beating on a cloth or by passing the stems through an iron comb. The process of removing the seeds is called rippling. The stalks are then retted or rotted in water to free the flaxen fibre from the woody core or boon of the stem. Two operations are necessary to separate the fibres from the woody part of the stem. Traditionally the flax was first broken by means of a wooden handle and grooved board, or by revolving grooved rollers, and then the boon or woody part was entirely separated from the fibre by a broad flat wooden blade called a scutching blade, or later by a machine in which a number of knives' attached to the arms of a vertical wheel hit the flax in the direction of its length. The flax was next heckled, or combed with a sort of iron comb, and was then ready for spinning. Research Flax
The Probert Encyclopaedia was designed, edited and programed by
Matt and Leela Probert
Abbreviations
Research Blind
