Columbia Encyclopedia

(Encyclopedia) Eustachi, Bartolomeo bärˌtōlōmĕˈō āˌo͞ostäˈkē [key], d. 1574, Italian anatomist. He lived in Rome from 1549 and taught at the Collegia della Sapienza (later the Univ. of Rome). He describ...

(Encyclopedia) tracheotomy trākēŏtˈəmē [key], surgical incision into the trachea, or windpipe. The operation is performed when the windpipe has become blocked, e.g., by the presence of some foreign object or b...

(Encyclopedia) player piano, an upright piano incorporating a mechanical system that automatically plays the encoded contents of a paper strip. This strip, perforated with holes whose position and length determine p...

(Encyclopedia) Hales, Stephen, 1677–1761, English physiologist and clergyman. From 1709 he was perpetual curate of Teddington. His experimental studies in animal and plant physiology contributed greatly to the pro...

(Encyclopedia)  CE5 Bernoulli's principle Bernoulli's principle, physical principle formulated by Daniel Bernoulli that states that as the speed of a moving fluid (liquid or gas) increases, the pressure within th...

(Encyclopedia) sea urchin, spherical-shaped echinoderm with movable spines covering the body. The body wall is a firm, globose shell, or test, made of fused skeletal plates and marked by regularly arranged tubercles...

(Encyclopedia) geyser gīˈzər [key] [Icel.], hot spring from which water and steam are ejected periodically to heights ranging from a few to several hundred feet. Notable geysers are found in Iceland, New Zealand,...

(Encyclopedia)  CE5 Reproductive system reproductive system, in animals, the anatomical organs concerned with production of offspring. In humans and other mammals the female reproductive system produces the femal...

(Encyclopedia) oasis ōāˈsĭs [key], an area within a desert where the water table reaches the surface, with enough moisture to permit the growth of vegetation. The water may come up to the surface in springs, or ...

(Encyclopedia) mortar, in warfare, term originally applied to certain types of artillery with high trajectories, but later applied to an infantry weapon that consists of a tube supported by a bipod that fires a proj...