f?"

"Yes," said Porthos.

"You said just now you came hither to study topography?"

"I did so."

"Tudieu! my friend, what fine things you will do!"

"How do you mean?"

"Why, these fortifications are admirable."

"Is that your opinion?"

"Decidedly it is. In truth, to anything but a regular siege, Belle-Isle
is absolutely impregnable."

Porthos rubbed his hands. "That is my opinion," said he.

"But who the devil has fortified this paltry little place in this
manner?"

Porthos drew himself up proudly: "Did not I tell you who?"

"No."

"Do you not suspect?"

"No; all I can say is that he is a man who has studied all the systems,
and who appears to me to have stopped at the best."

"Hush!" said Porthos; "consider my modesty, my dear D'Artagnan."

"In truth," replied the musketeer, "can it be you--who--oh!"

"Pray--my dear friend----"

"You who have imagined, traced, and combined between these bastions,
these redans, these curtains, these half-moons; and are preparing that
covered way?"

"I beg you----"

"You who have built that lunette with its retiring angles and its
salient angles?"

"My friend----"

"You who have given that inclination to the openings of your embrasures,
by means of which you so effectively protect the men who serve the
guns?"

"Eh! mon Dieu! yes."

"Oh! Porthos, Porthos! I must bow down before you--I must admire you!
But you have always concealed from us this superb, this incomparable
genius. I hope, my dear friend, you will show me all this in detail."

"Nothing more easy. Here lies my original sketch, my plan."

"Show it me." Porthos led D'Artagnan towards the stone that served him
for a table, and upon which the plan was spread. At the foot of the plan
was written, in the formidable writing of Porthos, writing of which we
have already had occasion to speak:--

"Instead of making use of the square or rectangle, as has been done to
this time, you will suppose your place inclosed in a regular hexagon,
this polygon having the advantage of offering more angles than the
quadrilateral one. Every side of your hexagon, of which you will
determine the length in proportion to the dimensions taken upon the
place, will be divided into two parts and upon the middle point you will
elevate a perpendicular towards the center of the polygon, which will
equal in length the sixth part of the side. By the extremities of each
side of the polygon, you will trace two diagonals, which