Minerals are solid, inorganic (not living) substances that are found in and on earth. Most are chemical compounds, which means they are made up of two or more elements. For example, the mineral…
Born: 1856Birthplace: Washington, Penn. Carborundum—Carborundum is the hardest surface made by humans and is second only to the diamond's hardness. Acheson created carborundum (silicon-carbide) by…
(Encyclopedia) ovenbird, common name for a member of the family Furnariidae, primitive passerine birds, which build elaborate, domed nests of clay or dig tunnels in the ground to lay their eggs.…
(Encyclopedia) Della RobbiaDella Robbiadĕlˌə rŏbˈēə, Ital. dĕlˈlä rôbˈbyä [key], Florentine family of sculptors and ceramists famous for their enameled terra-cotta or faience. Many of the Della…
(Encyclopedia) mortar, in building, mixture of lime or cement with sand and water, used as a bedding and adhesive between adjacent pieces of stone, brick, or other material in masonry construction.…
(Encyclopedia) reservoirreservoirrĕzˈəvôr, –vwär [key], storage tank or wholly or partly artificial lake for storing water. Building an embankment or dam to preserve a supply of water for irrigation…
Born: 1833Birthplace: Stockholm Improved explosive compound: dynamite—Accidents in the manufacturing and handling of nitroglycerin made Nobel aware of its danger in the fluid state. After much…
(Encyclopedia) soil, surface layer of the earth, composed of fine rock material disintegrated by geological processes; and humus, the organic remains of decomposed vegetation. In agriculture, soil is…
WHAT WAS BRONZE USED FOR? HOW WAS BRONZE FIRST MADE? WHO MADE THE FIRST BRONZE OBJECTS? FIND OUT MOREFrom around 9000 BC, people in different lands began to work with nuggets of soft metals,…
BEDROCKSEDIMENTARY ROCKSIGNEOUS ROCKSMETAMORPHIC ROCKSFIND OUT MOREThe Earth is covered in a layer of solid rock called the crust. Rocks are either SEDIMENTARY , IGNEOUS, or METAMORPHIC…
