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HEN Toots was four years old, his mamma thought she would let him have a
birthday party. She wrote the invitations on the prettiest little
paper, with funny frogs and dogs and cats in the corner, and each
little envelope was made to match. Twenty-five pretty little notes to
twenty-five dear little people, and every one came. No one else ever had
such a party before. Large tables were covered with books and toys,
all manner of games were waiting to be played, and in one corner of the
children's play-room was a table with bowls, plates, and pipes, and all
the children were invited to blow bubbles. Such fun as they had! Some
blew large and some blew small, and those who laughed hard blew none at
all. At last Toots and Robbie Mason began to see something in the soap
bubble, "beautiful colors like the rainbow," said Toots.
"More of them," said Robbie, and then all the children began to wonder.
"What makes it?" asked Robbie, eagerly; "I wish I knew?"
"I will tell you," said mamma. "When a ray of light is divided, as it
always is when it reaches an object on which to rest, it has different
colors, because each color has different powers and is refracted or
turned from its course. Let us cast a ray of light on this piece
of glass called a prism; now examine it closely, here we have seven
colors--red, orange, yellow, green, blue, indigo, and violet The red is
bent out of its course the least and it remains at the bottom; the blue
is refracted most and goes to the top. Now blow a nice bubble, little
Daisy, and I will explain the colors. You see the film is thicker
in some places than in others, and that causes different powers of
refraction or turning aside of the rays, and therefore, you observe
different colors; as the soap bubble constantly changes its thickness,
the rays vary or change also."
"There isn't any soap in the real rainbow in the clouds, is there?"
asked thoughtful Robbie.
"Oh, no; when the clouds opposite the sun are dark and rain is still
falling, the rays of the bright sun are divided by the rain drops as
they would be here with my prism." #
After the children grew tired of bubbles they had many games and a nice
supper, after which they went home saying it was the best party they
ever went to.
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