It attains its greatest perfection under cultivation, and, as it flowers throughout the summer, is used with good effect for garden borders; a variety, _M. strigulosa_, is more hairy and erect, and its flowers are smaller. In _M. versicolor_ the flowers are yellow when first open and change generally to a dull blue; sometimes they are permanently yellowish-white. Of the species in cultivation, _M. dissitiflora_, 6 to 8 in., with large handsome abundant sky-blue flowers, is the best and earliest, flowering from February onwards; it does well in light cool soils, preferring peaty ones, and should be renewed annually from seeds or cuttings. _M. rupicola_, or _M. alpestris_, 2 to 3 in., intense blue, is a fine rock plant, preferring shady situations and gritty soil; _M. azorica_ (a native of the Azores) with purple, ultimately blue flowers about half an inch across, has a similar habit but larger flowers; _M. sylvatica_, 1 ft., blue, pink or white, used for spring bedding, should be sown annually in August. FORGING, the craft of the smith, or "blacksmith," exercised on malleable iron and steel, in the production of works of constructive utility and of ornament. It differs from founding (q.v.) in the fact that the metal is never melted. It is essentially a moulding process, the iron or steel being worked at a full red, or white, heat when it is in a plastic and more or less pasty condition. Consequently the tools used are in the main counterparts of the shapes desired, and they mould by impact. All the operations of forging may be reduced to a few very simple ones: (1) Reducing or drawing down from a larger to a smaller section ("fullering" and "swaging"); (2) enlargement of a smaller to a larger portion ("upsetting"); (3) bending, or turning round to any angle of curvature; (4) uniting one piece of metal to another ("welding"); (5) the formation of holes by punching; and (6) severance, or cutting off. These include all the operations that are done at the anvil. In none of these processes, the last excepted, is the use of a sharp cutting tool involved, and therefore there is no violence done to the fibre of the malleable metal. Nor have the tools of the smith any sharp edges, except the cutting-off tools or "setts." The essential fact of the flow of the metal, which is viscous when at a full red heat, must never be lost sight of; and in forging wrought iron the judgment of the smith must be exercised in arranging the direction of the fibre in a way best calculated to secure maximum strength. [Illustration: FIG. 1.] Fullering and swaging.