(Encyclopedia) antiseptic, agent that kills or inhibits the growth of microorganisms on the external surfaces of the body. Antiseptics should generally be distinguished from drugs such as antibiotics…
(Encyclopedia) geodegeodejēˈōd [key], hollow, globular rock nodule ranging in diameter from 1 to 12 in. (2.54–30.5 cm) or more. Most geodes are partly filled with mineral matter; they have a thin…
(Encyclopedia) Arecibo Observatory, radio-astronomy facility located near Arecibo, Puerto Rico, part of the National Astronomy and Ionosphere Center. Conceived by, designed by, and built under the…
(Encyclopedia) Bond, George Phillips, 1825–65, American astronomer, b. near Boston, grad. Harvard, 1845. He became the assistant of his father, William Cranch Bond, and in 1859 succeeded him as…
Born: 1900 Altimeter. Prior to 1928, there was no reliable or accurate way for airplane pilots to know how far above the ground they were. The barometric altimeter, accurate within 20 feet,…
Born: 1900Birthplace: Cullom, Ill. Apparatus for testing acidity—Beckman founded Beckman Instruments, Inc. in 1935 with the development of a pH meter for measuring acidity and alkalinity. He also…
Source: The U.S. Government Printing Office After winning its independence from Great Britain in the Revolutionary War, the new country situated on the eastern seaboard of North America needed to…
Source: National Institute of Standards and Technology Physics Laboratory Celestial bodies—the sun, moon, planets, and stars > have provided us a reference for measuring the passage of time…
Economic Indicators It is said that the only way to get a unanimous opinion from a group of economists is to limit the group to one person. Economists are notorious for being unable to…
Born: 1903Birthplace: Findlay, Ohio Radio frequency mass spectrometer—Bennett studies in gases ionized by high voltage electricity was used in controlled thermonuclear fusion research. His radio…
