The doctor saw that Frank was nearly used up with the excitement, and insisted upon his having a cup of hot coffee and going to bed.
"You have made an important discovery," he said, "and the War Department ought to have something to say to you for it. Those fellows must have taken hundreds of dollars' worth of pipes, and I think we can recover them. I shall make a report to the Department, of course."
It was not long before nearly $1600 worth of lead pipes were recovered in Key West, where they had been taken; and when Frank went home late in the fall, as strong and brown as any mother could ask to see her son, he found a big letter waiting for him, without any stamps on the envelope, but printed in the corner, "War Department, Adjutant-General's Office. Official business."
"Mr. Frank Bethel," the letter said:
"Dear Sir,—The Secretary of War has learned from Dr. R. D. Murray, and from other official sources, of the recovery, through your efforts, of a large amount of government property stolen from Fort Jefferson.
"I am therefore directed to forward you the enclosed check for one hundred dollars, with the thanks of the War Department. Respectfully yours,
"J. W. Armstrong, Chief Clerk."
"Phew!" Frank exclaimed. "I'm glad the War Department don't know how scared I was down in those tanks!"