.

When calm was restored and all became eager to thank Captain Jeanniot,
they saw that he was gone.

* * * * *

Some years passed before I had an opportunity of talking to Lupin about
this business. He was in a confidential vein and answered:

"The business of the eighteen diamonds? By Jove, when I think that three
or four generations of my fellow-men had been hunting for the solution!
And the eighteen diamonds were there all the time, under a little mud
and dust!"

"But how did you guess?..."

"I did not guess. I reflected. I doubt if I need even have reflected.
I was struck, from the beginning, by the fact that the whole
circumstance was governed by one primary question: the question of time.
When Charles d'Ernemont was still in possession of his wits, he wrote a
date upon the three pictures. Later, in the gloom in which he was
struggling, a faint glimmer of intelligence led him every year to the
centre of the old garden; and the same faint glimmer led him away from
it every year at the same moment, that is to say, at twenty-seven
minutes past five. Something must have acted on the disordered machinery
of his brain in this way. What was the superior force that controlled
the poor madman's movements? Obviously, the instinctive notion of time
represented by the sun-dial in the farmer-general's pictures. It was the
annual revolution of the earth around the sun that brought Charles
d'Ernemont back to the garden at a fixed date. And it was the earth's
daily revolution upon its own axis that took him from it at a fixed
hour, that is to say, at the hour, most likely, when the sun, concealed
by objects different from those of to-day, ceased to light the Passy
garden. Now of all this the sun-dial was the symbol. And that is why I
at once knew where to look."

"But how did you settle the hour at which to begin looking?"

"Simply by the pictures. A man living at that time, such as Charles
d'Ernemont, would have written either 26 Germinal, Year II, or else 15
April, 1794, but not 15 April, Year II. I was astounded that no one had
thought of that."

"Then the figure 2 stood for two o'clock?"

"Evidently. And what must have happened was this: the farmer-general
began by turning his fortune into solid gold and silver money. Then, by
way of additional precaution, with this gold and silver he bought
eighteen wonderful diamonds. When he was surprised by the arrival of the
patrol, he fled int