twenty-five minutes past one at night
J. T. Maston , the brothers Blomsberry , and Engineer Murchison , without heeding these dangers , took their places in the air-chamber . The commander , posted on his bridge , superintended the operation , ready to stop or haul in the chains on the slightest signal . The screw had been shipped , and the whole power of the machinery collected on the capstan would have quickly drawn the apparatus on board . The descent began at twenty-five minutes past one at night , and the chamber , drawn under by the reservoirs full of water , disappeared from the surface of the ocean . The emotion of the officers and sailors on board was now divided between the prisoners in the projectile and the prisoners in the submarine apparatus . As to the latter , they forgot themselves , and , glued to the windows of the scuttles , attentively watched the liquid mass through which they were passing . The descent was rapid .