anybody says to you."

"That sounds incredible!" said Montague. "Who does it?"

"Wire tappers. It's dangerous work, but the pay is big. I have a
friend who once upon a time was putting through a deal in which the
telephone company was interested, and they transferred his wire to
another branch, and he finished up his business before the other
side got on to the trick. To this day you'll notice that his
telephone is 'Spring,' though every other 'phone in the
neighbourhood is 'John.'"

"And mail, too?" asked Montague.

"Mail!" echoed the Major. "What's easier than that? You can hold up
a man's mail for twenty-four hours and take a photograph of every
letter. You can do the same with every letter that he mails, unless
he is very careful. He can be followed, you understand, and every
time he drops a letter, a blue or yellow envelope is dropped on
top--for a signal to the post-office people."

"But then, so many persons would have to know about that!"

"Nothing of the kind. That's a regular branch of the post-office
work. There are Secret Service men who are watching criminals that
way all the time. And what could be easier than to pay one of them,
and to have your enemy listed with the suspects?"

The Major smiled in amusement. It always gave him delight to witness
Montague's consternation over his pictures of the city's corruption.