e, the bubble must descend slowly. Water is expanded,
too, in clouds; for, in that case, it is divided into millions of small
particles, by which it is spread out over a great deal of air, and
cannot descend without bringing a large portion of the air with it. Men
have contrived, on this principle, to make an apparatus to prevent being
hurt by falling from great heights."

"What is it?" said Rollo.

"Why, it is called a parachute. It is a sort of umbrella; in fact, it is
an umbrella, only made very large. It is folded up, and fastened under a
balloon, just over the car, which the man is in. Then, if the balloon
bursts, or any other accident happens to it, and the man begins to fall,
the parachute opens and spreads, and then the man falls very slowly. The
reason is, that the parachute takes hold of a large mass of air, and
brings it down with it; and so it cannot descend very fast."

* * * * *

A few days after this, Nathan said to Rollo, as they were playing in the
yard, that he wished that he had a parachute.

"I know where there is one," said Rollo.

"A parachute," said Nathan; "a real parachute?"

"Yes," said Rollo, "or, what is the same thing, a great umbrella."

"Is that just the same?" said Nathan.

"Yes," said Rollo; "for father said that a parachute was in fact only a
large umbrella; and father has got a large umbrella in the closet, and I
have a great mind to go and get it for a parachute."

"But you haven't got any balloon," said Nathan.

"O, no matter for that," said Rollo.

"Then how are you going to get up into the air?" asked Nathan.

"Why, I can climb up on the shed, and jump off that, and hold the
umbrella over my head."

Just at this moment, Rollo's cousin James came into the yard, and Rollo
ran to him, to explain to him about the parachute. After describing to
him the construction of it, and its use by men who go up in balloons, he
said he was going to get his father's umbrella, which would make an
excellent parachute.

"And then," continued he, "I am going to get upon some high place, and
jump off, and hold the parachute over my head, and then I shall come
down as light as a feather."

"O Rollo," said James, "I don't believe you will."

"Yes I shall," said Rollo: "you see the parachute is expanded, and so
brings down a great deal of air with it, and this makes it come very
slowly. Air is a _real thing_, James, and it keeps the parachute back a
great