2) echo, in acoustics. The Columbia Encyclopedia, Sixth Edition. 2001
...echo, in acoustics, reflection of a sound wave back to its source in sufficient strength and with a sufficient time lag to be separately distinguished. If a sound...

3) Echo, in Greek mythology. The Columbia Encyclopedia, Sixth Edition. 2001
...Echo, in Greek mythology, in Greek mythology, mountain nymph. She assisted Zeus in one of his amorous adventures by distracting Hera with her chatter. For this Hera...

4) communications satellite. The Columbia Encyclopedia, Sixth Edition. 2001
...artificial satellite that functions as part of a global radio-communications network. Echo 1, the first communications satellite, launched in 1960, was an instrumented...

5) Narcissus, in Greek mythology. The Columbia Encyclopedia, Sixth Edition. 2001
...in Greek mythology, beautiful youth who refused all offers of love, including that of Echo. As punishment for his indifference he was made to fall in love with his...

6) oilbird. The Columbia Encyclopedia, Sixth Edition. 2001
...It spends its days in dark caves, maneuvering by means of a batlike sonar device, or echo-locator, found in its ears. The oilbird emits a clicking sound at an audible...

7) Alsop, Richard. The Columbia Encyclopedia, Sixth Edition. 2001
...Dwight and others in writing light satiric verse for the Political Greenhouse and the Echo....

8) fruit bat. The Columbia Encyclopedia, Sixth Edition. 2001
...the possession of an independent, clawed second digit; it also depends on sight rather than echo-location in maintaining orientation. The Pteropodidae, or flying...

9) Franconia Mountains. The Columbia Encyclopedia, Sixth Edition. 2001
...Forest. Franconia Notch, a scenic, narrow pass (6 mi/10 km long), is west of the range. Echo and Profile lakes, and the Flume, a gorge with granite walls 70 ft (21...

10) Denver, University of. The Columbia Encyclopedia, Sixth Edition. 2001
...Observatory and, in cooperation with other institutions, high-altitude laboratories at Echo Lake and at Mt. Evans. There are centers for international education,...