from The Century Dictionary.
- noun An instrument used in determining the apparent velocity and the direction of motion of clouds.
from the GNU version of the Collaborative International Dictionary of English.
- noun (Meteorol.) An instrument for observing the clouds and their velocity.
from Wiktionary, Creative Commons Attribution/Share-Alike License.
- noun An
instrumentfor determining the directionof and angular velocityof clouds.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- noun a measuring instrument that uses a grid for measuring the altitude, direction, and velocity of movement of clouds
Sorry, no etymologies found.
While taking the observations at midnight, he noticed St. Elmo's fire, a "brush discharge" of electricity, on the points of the nephoscope.
Close by there was also a nephoscope for determining the motion of clouds.