nephodoscope

from The Century Dictionary.

• noun A form of nephoscope, devised by Fornioni in 1881, consisting essentially of a magnetic compass containing, above the needle, a circular plane mirror on which are drawn radial lines corresponding to the wind-rose. A rod with terminal sighting-eye or knob is pivoted to the edge of the mirror. The observation consists in keeping the reflections of the sight-point and of the cloud coincident as they pass from the center of the mirror off to the edge.