• WordNet 3.6
    • n nephoscope a measuring instrument that uses a grid for measuring the altitude, direction, and velocity of movement of clouds
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Webster's Revised Unabridged Dictionary
    • n Nephoscope (Meteorol) An instrument for observing the clouds and their velocity.
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Century Dictionary and Cyclopedia
    • n nephoscope An instrument used in determining the apparent velocity and the direction of motion of clouds. It usually consists of a horizontal mirror, with com pass-points or degrees drawn on the mirror or on the surrounding frame, together with an adjustable sighting-piece placed at various positions above the mirror. The sighting-piece serves as a fixed point for viewing the cloud-image as it moves away from the center of the mirror, upon which point the image is initially adjusted.
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Webster's Revised Unabridged Dictionary
Gr. ne`fos a cloud + -scope,


In literature:

Close by there was also a nephoscope for determining the motion of clouds.
"The Home of the Blizzard" by Douglas Mawson
In cloud work a nephoscope is essential.
"Wind and Weather" by Alexander McAdie
The nephoscope may be placed on a table, out of doors in fine weather, or close to a window from which the clouds to be observed can be seen.
"Practical Exercises in Elementary Meteorology" by Robert DeCourcy Ward