about seven o’clock
`` It 's as dark as a stack of black cats and another one throwed in . But breakfast is ready jest the same . '' The boys were soon at the table , and learned that nothing of importance had occurred during the night . The _ Mermaid _ had been kept going slowly down , and about seven o'clock registered more than fifty miles below the earth 's surface . Still there was no change in the outward surroundings . It remained as black as the interior of Egypt when that country was at its darkest . The powerful electrics could not pierce the gloom .