"Yes," demanded Virginia. "How do you pick them up?"

The young man laughed outright. Confidently he went on:

"Pick 'em up? It's so easy that I can't understand why no one ever
thought of it before. Did you ever see the way the fast expresses pick
up mail bags? Near the track there is an upright post, from which
extends an arm. On this arm is suspended the mail bag. The onrushing
train, which is travelling perhaps at a speed of a mile a minute, is
fitted on the outside with a sort of hook which catches the mail bag
and jerks it into the car. Well, that same idea can just as well be
applied to waiting passengers as to waiting mail bags. The passengers
would all be gathered together in a car which would wait on a siding
for the arrival of the express. By some mechanical
contrivance--exactly what it would be I haven't yet figured out--this
waiting car would be instantly switched on to the rapidly-moving
express--would become, so to speak, the rear car. The passengers would
go forward through the vestibule to take their seats in the train
proper and the emptied waiting car would then be unswitched and go
back to the station to begin the performance all over again--all this
while the train was going at top speed. Isn't that some idea? Isn't it
a dandy?"

Fanny was silent. Virginia, hardly able to control her merriment, took
up her book again. Jim was about to enter into further details when
suddenly there was a noise behind them. Fanny started up with a cry.

"Virginia! Look!" she exclaimed.