This section is from the book "The Boy Mechanic Vol. 2 1000 Things for Boys to Do", by Popular Mechanics Co.. Also available from Amazon: The Boy Mechanic, Vol2: 1000 Things for Boys to Do.
Use small shining Christmas-tree balls, about the size of a hickory nut, strung on strong black linen threads. The thread is put loosely over a hook at the back of the stage among the evergreens that are used for the background. The ends of the threads are brought, like a pair of reins, to the front of the stage, diagonally, and there manipulated by some one in a wing near the front, standing high enough to prevent the threads from touching the heads of the actors. These bright little particles darting back and forth among the trees appear very lifelike, and with the addition of a crescent moon just peeping through the trees, the likeness to a summer night is quite striking.
The moon effect is made by using a piece of dark cardboard, about 2 ft. square, covered thickly with small green boughs, and by cutting a crescent-shaped opening in the center, covering it with yellow tissue paper. This cardboard is placed well back in the trees and a lantern hung behind it. - Contributed by Miss S. E. Jocelyn, New Haven, Conn.