"Now that," I broke in emphatically, "is a defect I have discovered
in----"

But he put up his hand to stop me. "It slightly deteriorates, I say,
with the passage of time." He paused a moment impressively. "No one has
hitherto discovered any system which will accurately record the speed of
a vehicle or of any rotary movement and register it at the lowest as at
the highest speeds." He paused again for a still longer period in order
to give still greater emphasis to what he had to say. He concluded in a
new note of sober triumph: "I have solved the problem!"

I thought this was the end of him, and I got up and beamed a
congratulation at him and asked if he would drink anything, but he only
said, "Please sit down again and I will explain."

There is no way of combating this sort of thing, and so I sat down, and
he went on:

"It is perfectly simple...." He passed his hand over his forehead. "It
is so simple that one would say it must have been thought of before; but
that is what is always said of a great invention.... Now I have here"
(and he opened out his foolscap) "the full details. But I will not read
them to you; I will summarize them briefly."

"Have you a plan or anything I could watch?" said I a little anxiously.

"No," he answered sharply, "I have not, but if you like I will draw a
rough sketch as I go along upon the margin of your newspaper."