ore heat-treating furnace
31Inventions in medieval Islam — A significant number of inventions were developed in the medieval Islamic world, a geopolitical region that has at various times extended from Al Andalus and Africa in the west to the Indian subcontinent and Malay Archipelago in the east.… …
32Zinc oxide — Other names Zinc white Calamine Identifiers …
33painting, Western — ▪ art Introduction history of Western painting from its beginnings in prehistoric times to the present. Painting, the execution of forms and shapes on a surface by means of pigment (but see also drawing for discussion of depictions in …
34William Kelly (inventor) — William Kelly (August 22, 1811 February 11, 1888), born in Pittsburgh, Pennsylvania, was an American inventor. Kelly studied metallurgy at the Western University of Pennsylvania. Instead of getting a job as a scientist, Kelly, his brother, and… …
35Alchemy — Alchemist redirects here. For other uses, see Alchemist (disambiguation). For other uses, see Alchemy (disambiguation). Page from alchemic treatise of Ramon Llull, 16th century Alchemy is an influential philosophical tradition whose early… …
36Tantalum — (pronEng|ˈtæntələm) (formerly tantalium IPA|/tænˈtæliəm/) is a chemical element with the symbol Ta and atomic number 73. A rare, hard, blue grey, lustrous, transition metal, tantalum is highly corrosion resistant and occurs naturally in the… …
37platinum group — ▪ chemical element group Introduction six metals, in order of increasing atomic weight, ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), and …
