Earth Sciences and Ecology Question #1088

Jon, a 10 year old male from Ottawa asks on December 6, 2002,

Who invented the nephoscope? When was it invented?

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The answer

Keith Heidorn, PhD answered on December 17, 2002

Nephoscopes are used for measuring the speed and direction of cloud motion, so the units should be those of speed and direction.

The word "nephoscope" is given an origin of 1881 and I have seen a photo of an instrument from 1884.

There is also a Marvin nephoscope that was devised by Professor Marvin in 1896 for the U.S. Weather Bureau stations. Moore, (Descriptive Meteorology --1908) mentions that an unnamed Swedish meteorologist first used a mirrored nephoscope about 1888. Cleveland Abbe amost simultaneously and independently used the instrument, which is likely the Marvin model.

As far as I can determine, the comb nephoscope was invented by L. Besson sometime before 1918.

Among the various forms of this instrument are the nephodoscope of Fornioni, the marine nephoscope of Finemann, the simple mirror with attachments used by Clayton, the cloud camera of Vettin, and the altazimuths of Mohn and Lettry.

There are several types of nephoscope: the comb nephoscope developed by Besson; the mirror nephoscope developed by Finemann; and the grid nephoscope, a variation on the comb modified by the Norwegians.

Movement of clouds are coded with respect to the compass direction toward which the phenomena is moving. This is usually coded as tens of degrees in any measurement system. For example, a southward moving cloud is moving to 180 degrees and thus coded as 18 in a numerical report. It might also be coded in a remarks or text report using the direction in compass points (8-point compass) such as: CB MOV S, meaning cumulonimbus moving south.

This English website has pictures and early descriptions of nephoscopes.

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