Abstract: A method for providing strong adhesion of two ceramic articles to each other or one ceramic article to an article of metallic copper, which method comprises applying, in the former adhesion, a powder mixture of CuS--LaCrO.sub.3 --SiO.sub.2 --Cu to the opposed surfaces of the two ceramic articles or, in the latter adhesion, a powder mixture of CuS--LaCrO.sub.3 --SiO.sub.2 to the opposed surfaces of the ceramic article and the article of metallic copper and, thereafter, heating the pair of articles in the air at a temperature of from 1000.degree. to 1200.degree. C.

Abstract: As a first step to bend a glass along a line traversing the plate, external heat is applied to the glass plate such that a narrow zone containing the entire length of the bending line is heated more intensely than the remaining area to reach a temperature at which the glass does not yet soften but exhibits an appreciable lowering of its electrical resistivity. Then an electric current is caused to flow through the glass in the intensely heated zone from one terminal of the bending line to the other terminal, until the glass is softened only in this zone, i.e. along the bending line by the Joule effect of the current. In this state, desired manner of bending is achieved by the use of a suitably shaped bending die.

Abstract: The contacted edge portions of plate glasses to be joined are locally heated to a temperature higher than in the other portions of the plate glasses, after the whole of the plate glasses is heated. Electric current is then passed to the edge portions in order to further heat the edge portions so that the edges of the plate glasses are molten and welded together.

Abstract: The edge portion of a plate glass is locally heated to a temperature higher than that in the other portion of the plate glass, after the whole of the plate glass is heated. Electric current is thereafter applied to the edge portion of the plate glass in order to further heat the edge portion so that the edge of the plate glass is slightly melted.

Abstract: A thin coating of silver is formed fast on the surface of a nitride type ceramic article by coating the surface of the ceramic article with a mixture consisting of copper sulfide and kaolin, subjecting the coated article to a thermal treatment in a nitrogen-containing atmosphere at a temperature in the range of from 900.degree. to 1300.degree. C., then overcoating the thermally treated ceramic article with silver carbonate and heating the overcoated article again in the nitrogen-containing atmosphere at a temperature in the range of from 700.degree. to 900.degree. C.