I said, "Eh, what?"

He said again "I beg your pardon" in the tones of a man who almost
commands, and having said this he put his hat on the table, dragged a
chair quite close to mine, and pulled a folded bunch of foolscap sheets
out of his pocket. His manner was that of a man who engages your
attention and has a right to engage it. There were no preliminaries and
there was no introduction. This was apparently his manner, and I
submitted.

"I have here," he said, fixing me with his intense eyes, "the plans for
a speedometer."

"Oh!" said I.

"You know what a speedometer is?" he asked suspiciously.

I said yes. I said it was a machine for measuring the speed of vehicles,
and that it was compounded of two (or more) Greek words.

He nodded; he was pleased that I knew so much, and could therefore
listen to his tale and understand it. He pulled his grey baggy trousers
up over the knee, settled himself, sitting forward, and opened his
document. He cleared his throat, still fixing me with those eyes of his,
and said--

"Every speedometer up to now has depended upon the same principle as a
Watt's governor; that is, there are two little balls attached to each by
a limb to a central shaft: they rise and fall according to their speed