What is a Camera Obscura?
A small box or dark room into which the light is admitted through a lens.
What is a Stereoscope?
It is an instrument exhibiting the effects and advantages of seeing with two eyes. The instrument is so constructed that from a flat picture we may see the solid body in its reality in nature.
What is a Kaleidoscope?
An instrument invented by Sir David Brewster, consisting of a tube with slips of reflecting glass so arranged in the interior that small beads, bits of colored glass, and similar things are, by revolving the tube, thrown into an endless variety of beautiful shapes.
CHAPTER XXI.
Electricity, Electric Currents, Electric Battery, Electrotyping, Stereotyping, Telegraph, Ocean Cable, Lightning Rod, The Gulf Stream, The Mt. Cenis Tunnel, The Suez Canal, Suspension Bridges, Eminent Americans.
What is the nature of Electricity?