Every provision against immediate danger had been made. By means of preconcerted signals, the inmates could have themselves drawn up, let down, or carried laterally in whatever direction they pleased. By barometers and other instruments they could readily ascertain the pressure of the air and water, also how far they had descended and at what rate they were moving. The Captain, from his bridge, carefully superintended every detail of the operation. All signals he insisted on attending to himself personally, transmitting them instantly by his bell to the engineer below. The whole power of the steam engine had been brought to bear on the windlass; the chains could withstand an enormous strain. The wheels had been carefully oiled and tested beforehand; the signalling apparatus had been subjec
