About four o'clock
`` I only wish you to observe that , after having made so many objections to my project , you are now crushing me with arguments in its favour ! '' The preparations for this audacious attempt now began . The powerful pumps of the Nautilus were working air into the reservoirs and storing it at high pressure . About four o'clock , Captain Nemo announced the closing of the panels on the platform . I threw one last look at the massive iceberg which we were going to cross . The weather was clear , the atmosphere pure enough , the cold very great , being 12 ° below zero ; but , the wind having gone down , this temperature was not so unbearable . About ten men mounted the sides of the Nautilus , armed with pickaxes to break the ice around the vessel , which was soon free .