(Encyclopedia) fluoroscopefluoroscopefl&oobreve;rˈəskōp [key], instrument consisting of an X-ray machine (see X ray) and a fluorescent screen that may be used by physicians to view the internal…
People and animals have worked together for thousands of years. Some dogs guard against enemies, while others herd cattle. Cats hunt mice and other rodents, preventing them from stealing food and…
(Encyclopedia) refraction, in physics, deflection of a wave on passing obliquely from one transparent medium into a second medium in which its speed is different, as the passage of a light ray from…
actressBorn: 12/22/1922 Birthplace: Los Angeles, CADied: 10/16/2010 (Santa Monica, CA) Barbara Billingsley was born Barbara Lillian Combes on Dec. 22, 1915, in…
(Madame C. J. Walker)businesswoman, philanthropistBorn: 12/23/1867Birthplace: Delta, La. After a series of bereavements that left her orphaned at 6 and widowed at 20, she and her daughter A'Lelia…
(Encyclopedia) Willughby, FrancisWillughby, Franciswĭlˈəbē [key], 1635–72, English naturalist. He is known especially for his early systematic work on birds and fishes, in which he made some of the…
