the 12th of November at 6 a.m.
`` As I am not going with you , '' said the brave artilleryman , `` the least I can do will be to live in the projectile for a week . '' It would have been ungracious to refuse him . His wish was complied with . A sufficient quantity of chlorate of potash and caustic potash was placed at his disposition , with provisions for a week ; then having shaken hands with his friends , on the 12th of November at 6 a.m. , after having expressly recommended them not to open his prison before the 20th at 6 p.m. , he crept into the projectile , the iron plate of which was hermetically shut . What happened during that week ? It was impossible to ascertain . The thickness of the projectile 's walls prevented any interior noise from reaching the outside .