"We must walk down," urged Merritt. "There is so much to see in the rare stones and relics set all the way down in the inside of the tower walls,—so I've been told."
"If we read all the inscriptions it will take too much time," warned Rob, "but we can spend half an hour more here."
At the end of that time the boys emerged from the lofty shaft with a feeling that they had been on a long journey. From all over the world had come the mementos that they had just seen,—from foreign battlegrounds, from fields of exploration, and from places of historic sentiment.
"That was as good as a lesson in 'Ancient and Modern History,'" claimed Tubby, reluctant to go.
"Yes, but now let's beat it to the station," Andy urged, "or we'll miss our train."
"Should you care if we missed it, boys?" asked Rob, stopping deliberately and facing them.
"What do you mean?" inquired Merritt.
"Just this: We have purposely refrained from giving our folks the exact date of our coming home, and this itinerary does not bind us to any definite train. Why not get a glimpse of the Smithsonian Institute, visit the Congressional Library this evening and take the midnight sleeper for New York? Then we can walk in at home soon after breakfast is over to-morrow morning and surprise everybody. What do you say?"
"We say 'Yes'!" chimed in the three other voices.
"It is a great idea," Merritt added. "They say that the Library is really wonderful at night."