Answer:
The main idea of “The Gift of the Magi” is that the value of a gift is in the giver, rather than the gift itself. Jim and Della, out of their love for each other, purchased a gift that required them to sacrifice something that was precious to them.
The machinery worked so badly that the revolution of the turret was stopped.
If you mean dispersion it mean splitting light into 7 parts.
They are used to create artificial rainbow effects
