Page:Landscape Painting by Birge Harrison.djvu/39

 be harmonious and beautiful in proportion to the harmony and beauty of the music upon which it is based.

This is guesswork, of course, but it rests upon a strong basis of probability. Our actual knowledge of the subject is at present limited to mathematics. The velocity of the impulses has been noted and the number of the vibrations has been counted. We know those of sound to be comparatively slow, there being but 4,000 vibrations to the inch in the highest treble note of the piano. Above this on the ascending scale comes a long series of vibrations of which we know little or nothing; and it is not until we reach 36,000 vibrations to the inch that we come again within the range of human sensory consciousness. This number represents the rate of vibrations in the red note of our prismatic scale. The rate of vibration increases