twelve o'clock
Captain Nemo , furnished with a lenticular glass which , by means of a mirror , corrected the refraction , watched the orb sinking below the horizon by degrees , following a lengthened diagonal . I held the chronometer . My heart beat fast . If the disappearance of the half-disc of the sun coincided with twelve o'clock on the chronometer , we were at the pole itself . `` Twelve ! '' I exclaimed . `` The South Pole ! ''