"The doctor admits no one. In his studio he is as inaccessible as a Turkish sultan in his harem. I will introduce you in the dining-room, as it is now just dinner-time."

They betook themselves to the dining-room, and soon after they heard the sound of a bell.

"He is just now called to table," said Richard. "He does not allow the servant to enter his room, and for that reason a bell has been hung there."

"How particular he is!" said the professor.

A door of the ante-room was opened, quick steps were heard, and Klingenberg hastily entered and placed himself at the table, as at a work that must be done quickly, and then observed the stranger.

"Doctor Lutz, professor of history in our university," said Frank, introducing him.

"Doctor Lutz--professor of history," said Klingenberg musingly. "Your name is familiar to me, if I am not mistaken; are you not a collaborator on Sybel's historical publication?"

"I have that honor," answered the professor, with much dignity.

They began to eat.

"You read Sybel's periodical?" asked the professor.