up. To effect this a second prism may be placed near the first, but reversed in position, one of the edges being upward ; or a double convex lens, like a reading glass, may be placed so as to embrace all the colours, and in the focus of the glass there will be white light only. The same may be… … To return to the rainbow, the question remains, how are the colours produced in a rainbow ? There are not prisms hanging in the air, by which the rays are dis- persed. True, but we must first consider what shape the rain drops are. When we look at the rain it appears to fall in lines , and it is by…
Light · Color · Optical illusions · Optics
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