INFLUENCE OF LIGHT UPON COLOURS.

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such as that represented in PI. IX. The pieces, on leaving the dye-beck, entera large tank of water, where they are well agitated: hence they pass betweentwo cylinders under a torrent of water discharged upon them from above ;they next descend into a narrower tank, into which water falls from a widepipe ; they are then passed between a second pair of cylinders, still exposedto a copious descending shower of water.

The process of drying is conduced in various manners, according to thenature of the goods. Cloth is generally stretched out on “ tenters ” (extenders)in the open air, or in large sheds heated by steam-pipes. Certain colours verysusceptible to the adtion of light, such as safflower shades on any kind ofmaterial, are best dried in the dark, by means of a current of cold air drivenover them by means of a fan. Worsted and mixed stuffs, such as merinos,coburgs, delaines, &c., are dried by passing over rollers heated by steam, asshown in PI. X.

With the modern rage for apparent cheapness the process of finishing hasgrown in importance. Goods, both white and coloured, depend to a greatextent for their appearance, and even for their body, not so much upon textilefibres—whether animal or vegetable—as upon a variety of dressings, finishings,and weightings, for which the wool or cotton serves merely as a kind of frame-work. Gums, Iceland moss, starches, glue, sulphates of lime and baryta,Epsom salts, and chloride of magnesium, dexterously mixed and introduced,hide a multitude of deficiencies, and convert a weak, straggling, canvass-likenetwork into a smooth, full, and compadt article—until it has paid its firstvisit to the wash-tub, when the truth is revealed. These additions are mademost largely to cotton goods: woollen cloths are weighted to some extentwith the chloride of magnesium, which—from its high specific gravity, itspower of attradting moisture from the air, and its want of adtion upon colours—receives the preference.

Stuffs, previous to finishing, are moistened with an extremely fine shower,produced by allowing water to descend through a sieve of silk. They are thenpassed over the finishing-machine shown in PI. XI., consisting of threehollow cylinders, the temperature of which can be rapidly raised or lowered.This operation requires a very considerable amount of skill and experience onthe part of the workmen, and on its corredt execution the appearance of thegoods greatly depends. The last process to which stuffs are subjedted in dye-works is hot-pressing. Between each fold of the piece is placed a layer of asmooth, elastic paper, made expressly for this purpose. At certain intervalsplates of cast-iron, strongly heated, are inserted, and the whole is submittedto the adtion of the hydraulic press.

Influence of Light upon Colours.

In its adtion upon colours light has been compared to the Indian Trimurti,combining the triple fundtions of generator, modifier, and destroyer. Indarkness we are told organic colours are not produced, whilst the more intensethe light the more brilliant and varied are the hues developed. In supportof this view a great body of fadts may be brought forward. That the flowers,the fruits, the insedts of tropical regions are more richly coloured than thoseof climates where the sun has less power is a truism. If we argue that thecolours thus produced may be due, wholly or partially, to the higher