Abrasives
term applied to substances used in polishing and grinding. They include implements fashioned from natural materials, such as grindstones, millstones, whetstones, etc., mineral substances used in a granulated form and artificial abradants.
The familiar grindstone, known from the earliest times, is made from a gritty, tenacious sandstone, found in abundance ABRUZZI in Germany and the British Isles, tainous, the Apennines here reaching and plentiful in Ohio and other Western States. Millstones and buhrstones, the latter of which are largely imported from cereals, cement rock and certain minerals.
The increasing use of the roller process in flour-making has decreased the de- 1,550,000. stones, and whetstones are chiefly of American origin, although an appreciable amount is imported from Belgium, Italy, and France. Pumice is a volcanic ash is found in Utah and Nebraska, and is also brought from the Lipari Islands.
Crystalline quartz is used for sandpaper, garnet for woodworking and shoemaking and corundum for metals, the latter being the hardest material known except the steels. Carborundum or carbide of silicon is extensively used in difficult tasks. One of the newest abrasives is electrite, which has a composition between alundum and carborundum. The water power of Niagara Falls is used for the treatment and manufacture of abrasives in great plants that have been established near the Falls.
ABRUZZI (äb-röts'ē), PRINCE LUIGI ment and manufacture of abrasives in great plants that have been established OF, Italian explorer; born in Madrid, Jan. 29, 1873; nephew of King Humbert; in May, 1899, he started on an expedition, in the specially prepared steamer "Star of Italy," for Franz Josef Land, intending, when frozen in, to use sledges in a search for the North Pole and the balin May, 1899, he started on an expedition, to Norway in September, 1900, after having reached a point in latitude 86° 33′ N., surpassing Nansen's farthest N. record by 19'. In 1906 he led an expedition search for the North Pole and the balloon explorer, Dr. Andrée. He returned to Norway in September, 1900, after hav- ing reached a point in latitude 86° 33' 16,600 feet high, whose summit, so far as known, had never before been reached.
In 1909, he reached the top of Mt. Austen in India, 24,000 feet. During the war with Tripoli, he headed an Italian squadron operating in the Adriatic and Mediterranean. At the outbreak of the World War, he was appointed Commander-in-Chief of the Italian navy, and after the entrance of his own country into the conflict in May, 1915, he acted in co-operation with the allied admirals in controlling the waters of southern Europe.