Emery
3 of the 6 encyclopedias on this shelf carry an entry for Emery. All 3 are reproduced below, so you can see where they agree and where they differ.
Aiton's Encyclopedia (1910)
a fine grained, black sandstone. Its color is due to the presence of iron. In use it may be cut into the shape of a grindstone and caused to rotate on an axis; but it is so difficult to work that it is really easier to pound the stone into a powder and build it up into the required shape again with cement. Rubber and copper are frequently added to the composition to diminish danger from breaking. The emery paper on sale at hardware stores consists of paper coated with glue and dusted with emery powder. Its principal use is in smoothing metal and wood. Emery cloth is prepared in the same way. It is used chiefly for polishing metals. Emery is found in Massachusetts, Georgia, and North Carolina ; but the world's chief supply is obtained from Asia Minor and the Grecian Archipelago. Emery ranks next to the diamond in hardness. It will cut glass or any other material save the diamond. See Corundum ; Aluminum ; Sapphire
Collier's New Encyclopedia (1921)
HENRY CROSBY, an Amereconomist, born at Ellsworth, Me., ican e in 1872. He graduated from Bowdoin College in 1892 and took post-graduate courses at Columbia and the University of Berlin. He was instructor and professor of political economy at Bowdoin from 1894 to 1900, and from 1900 to 1915 was Professor of Political Economy at Yale. From 1909 to 1913 he was chairman of the United States Tariff Board. He was foreign ign representative of the Guaranty Trust Company of New York from 1916. During the World War he was arrested while traveling in Russia and for some time held prisoner. He wrote "Speculation on the Stock and Produce Exchanges of the United States" (1896); "Politician, Party, and People" (1913). He also contributed many articles on economic and political questions to various magazines. EMEU. See EMU. EMIGRATION. See IMMIGRATION.
American Watchmaker and Jeweler (1892)
The dark colored and non-transparent variety of corundum. See Corundum.
What Has Changed in the Last Century
Aiton's 1910 account calls emery "a fine grained, black sandstone" whose colour comes from iron; the 1892 watchmakers' volume is nearer the mark in defining it as a dark, opaque variety of corundum, and that is the modern view — emery is a natural rock of aluminium oxide mixed with iron oxides such as magnetite and hematite. The bigger change is commercial: manufactured abrasives, above all silicon carbide (patented by Edward Acheson in the 1890s) and fused aluminium oxide, took over the grinding-wheel trade in the decades after these entries, so the Turkish and Greek deposits Aiton's names as "the world's chief supply" no longer dominate; natural emery survives largely in nail-files, non-slip stair treads and traditional emery cloth. Aiton's claim that emery "ranks next to the diamond in hardness" also no longer holds, since silicon carbide, boron carbide and cubic boron nitride (developed by General Electric in the 1950s) all outrank corundum. The Collier's entry, misfiled here, is for the Yale economist Henry Crosby Emery, chairman of the U.S. Tariff Board, who died a few years after the 1921 volume appeared.
Written for this edition, 2026.