—Merchant of Venice.
The spheres were conceived to be crystalline or glassy fabrics arranged over one another like a nest of bowls reversed. In the substance of each sphere one or more of the heavenly bodies was supposed to be fixed, so as to move with it. As the spheres are transparent we look through them and see the heavenly bodies which they contain and carry round with them. But as these spheres cannot move on one another without friction, a sound is thereby produced which is of exquisite harmony, too fine for mortal ears to recognize. Milton, in his “Hymn on the Nativity,” thus alludes to the music of the spheres:
“Ring out, ye crystal spheres!
Once bless our human ears
(If ye have power to charm our senses so);
And let your silver chime
Move in melodious time,
And let the base of Heaven’s deep organ blow;
And with your ninefold harmony
Make up full concert with the angelic symphony.”