And then the pleasant-spoken young officer led the way to a lift, and,
touching a button, the three descended from the top of the mountain to
the valley beneath.

"On the counterweight system," explained the A.D.C. "We cribbed
the idea from Folkestone, and Lynmouth. And here, _Mr. Punch_, is
something that will interest you. We absolutely howled at that sketch
of yours showing the mechanical policeman. Don't you know--old woman
puts a penny in the slot and stops the traffic? And here's the idea
developed. See that mechanical sentry. I put a penny in the slot, and
he pays me the usual compliment. He shoulders arms, as I am only a
captain--worse luck! If I were of field rank he would come smartly
to the present."

And sure enough the mechanical soldier saluted.

"It's not half a bad idea," continued the agreeable A.D.C. "You see
sentry-go is awfully unpopular, and a figure of iron in times of peace
is every bit as good as a man of brass. The pence go to the Canteen
Fund along with the fines for drunkenness. It seems reasonable enough
that a fellow, if he wants to be saluted, should pay for the
swagger. If a fellow likes to turn out the guard, he can do it with
sixpence--but then of course he hasn't the right unless his rank
permits it--see?"

By this time the mechanical soldier had returned to the slope, and was
parading his beat in a somewhat jerky manner.

"And now what would you fellows like to do?" asked the A.D.C. "Pardon