These regions present magnificent examples of dry erosion by wind-borne sand, which acts as a powerful sand blast etching away the rocks and producing most beautiful sculpturing.
His work in black-and-white, his admirable illustrations in brushwork of Edinburgh and its neighbourhood, and also his pen-drawings, about which it has been declared that "his work contains all the subtleties and refinements of a most delicate etching," must also be noted.
In some places wood-carving has been brought to considerable perfection; and native artists know how to engrave on metal both by etching and the burin.
Dark coloured micas are strongly pleochroic. Accurate determinations of the optical orientation, as well as the symmetry of the etching figures on the cleavage planes, seem to suggest that the micas, except muscovite, may be anorthic rather than monoclinic in crystallization.
In the 17th and 18th centuries the processes of scratching, engraving and etching were brought to great perfection.
A little before his death he had also formed a scheme of writing a Discourse on the Arts of Painting, Sculpture, Etching, &c., but when he died he had made but little progress with it.
Fluorides can be readily detected by their power of etching glass when warmed with sulphuric acid; or by warming them in a glass tube with concentrated sulphuric acid and holding a moistened glass rod in the mouth of the tube, the water apparently gelatinizes owing to the decomposition of the silicon fluoride formed.
Besides these three masterpieces of line-engraving, the same years, 1512-1515, found DUrer occupied with his most important experiments in etching, both in dry-point ("The Holy Family and Saints" and the "St Jerome in the Wilderness") and with the acid bath.
In the " etching " process the surface of the glass is etched by the chemical action of hydrofluoric acid, the parts which are not to be attacked being covered with a resinous paint.
Schwanhart of the process of etching on glass by means of hydrofluoric acid, and the rediscovery by J.
This structure can be rendered visible by superficial etching with dilute acid; and as the minuter crystals dissolve more quickly than the larger ones, the surface assumes a frosted appearance (moiree metallique).
It is decorated with diamond or steel-point etching, and bears on one side the date 1586, and on the opposite side the words " In God is al mi trust."
Among engravings of the same time are three Madonnas, the apostles Thomas and Paul, a bagpiper and two peasants dancing, and three or four experiments in etching on plates of iron and zinc. In wood-engraving his energies were almost entirely given to bearing a part - which modern research has proved to have been not nearly so large as was traditionally supposed - in the great decorative schemes commanded by the Emperor Max in his own honour, and devised and carried out by a whole corps of men of letters and artists: namely, the Triumphal Gate ..and the Triumphal March or Procession.
Wood engraving kept its ground for a considerable period, especially in Germany, but copper in the end supplanted it, and owing to the beauty and clearness of the maps produced by a combination of engraving and etching it still maintains its ground.