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Umber
A variety of hematite ore, composed of oxide of iron 48, oxide of manganese 20, silex 13, alumina 5, water 14. It is found in Cyprus…
Undercut
A pattern or model is said to be undercut when its lower dimensions are largest--exactly opposite to taper or draught. Such patterns may in…
Universal Rolling-mill
A compound rolling-mill consists of a pair of vertical rolls working in combination with another pair of horizontal ones, which act to…
Uranium
A metal found in a few minerals, as pitchblende, which is an oxide, and uranite, which is a phosphate. The former is its principal ore. The…
Uchatius Bronze – Upright Runner
See TELEGRAPH-WIRE. This steel is produced from iron which has been granulated by plunging into water and then melted along with brown…