copper-lead bearing
121Natural History (Pliny) — Naturalis Historia, 1669 edition, title page. The title at the top reads: Volume I of the Natural History of Gaius Plinius Secundus. The Natural History (Latin: Naturalis Historia) is an encyclopedia published circa AD 77–79 by Pliny the… …
122chemistry — /kem euh stree/, n., pl. chemistries. 1. the science that deals with the composition and properties of substances and various elementary forms of matter. Cf. element (def. 2). 2. chemical properties, reactions, phenomena, etc.: the chemistry of… …
123international relations — a branch of political science dealing with the relations between nations. [1970 75] * * * Study of the relations of states with each other and with international organizations and certain subnational entities (e.g., bureaucracies and political… …
124sulfur — /sul feuhr/, n. 1. Also, esp. Brit., sulphur. Chem. a nonmetallic element that exists in several forms, the ordinary one being a yellow rhombic crystalline solid, and that burns with a blue flame and a suffocating odor: used esp. in making… …
125Western architecture — Introduction history of Western architecture from prehistoric Mediterranean cultures to the present. The history of Western architecture is marked by a series of new solutions to structural problems. During the period from the… …
126Hard disk drive — Hard drive redirects here. For other uses, see Hard drive (disambiguation). Hard disk drive Mechanical interior of a modern hard disk drive Date invented 24 December 1954 [1] …
127Nickel — This article is about the chemical element. For other uses, see Nickel (disambiguation). cobalt ← nickel → copper ↑ Ni ↓ Pd …
128hand tool — any tool or implement designed for manual operation. * * * Introduction any of the implements used by craftsmen in manual operations, such as chopping, chiseling, sawing, filing, or forging. Complementary tools, often needed as auxiliaries to… …
