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A revolving disk on which figures drawn in different relative attitudes are seen successively, so as to produce the appearance of an object in actual motion, as an animal leaping, etc., in consequence of the persistence of the successive visual impressions of the retina. It is often arranged so that the figures may be…

A flamingo.

A genus of birds which includes the flamingoes.

An instrument for studying the motions of sounding bodies by optical means. It consists of a tube across the end of which is stretched a film of soap solution thin enough to give colored bands, the form and position of which are affected by sonorous vibrations.

An instrument for observing or exhibiting the motions or properties of sounding bodies; especially, an apparatus invented by König for testing the quality of musical strings.

An apparatus for observing the phosphorescence produced in different bodies by the action of light, and for measuring its duration.

A device for giving shifting effects of color to a photograph. The unmounted print, made translucent, is illuminated from behind with colored light.

Anything employed for the observation of light or luminous effects.

Of or pertaining to the photoscope or its uses.

A telescope adapted for taking photographs of the heavenly bodies.

A brown coloring matter found in certain algæ.

ca, including the chitons. The back is covered by eight shelly plates. Called also Polyplacophora. See Illust. under Chiton, and Isopleura.

A rain gauge.

An instrument consisting essentially of a polarizer and an analyzer, used for polarizing light, and analyzing its properties.

Of or pertaining to the polariscope; obtained by the use of a polariscope; as, polariscopic observations.

The art or rocess of making observations with the polariscope.

An opera glass or field glass with an oblique mirror arranged for seeing objects do not lie directly before the eye; -- called also diagonal, or side, opera glass.

See Placophora.

A glass which makes a single object appear as many; a multiplying glass. Hutton.

An instrument, similar to the phenakistoscope, for presenting to view, or projecting upon a screen, images the natural motions of real objects.