twelve o'clock exactly
`` I never heard such a racket , '' answered Carl ; `` our skipper must be out of his head not to start the vipers . '' The captain appeared in the doorway . There was a pleasant smile on his face , and he did not seem at all alarmed at the menacing aspect of affairs . `` Gentlemen , '' he said , `` we resume our voyage at twelve o'clock exactly . '' `` It is now a quarter to , '' said the professor , regarding his chronometer . `` Precisely . I shall open the flap , and take in air directly . ''