concerned, both to the owners, shippers and insurers, on shore, and the crew of the vessel, that the independence of the mate, as the journalist of the voyage, should be preserved. The master, from the power of his office, can at all times make the situation of a mate who has displeased him extremely disagreeable, and from this cause has great indirect influence over him; the law and the custom should therefore be strictly adhered to which rightly make the chief officer, in this respect, in a manner the umpire between the master and the crew, as well as between all on board and the parties interested on shore. The law also makes the chief mate the successor to the master, in case the latter should die, or be unable to perform the duties of his office; and this without any action on the part of the crew. It is always important, therefore, that, to the practical seamanship and activity necessary for the discharge of the proper duties of his office, the mate should add a sufficient knowledge of navigation to be able to carry the ship on her voyage in case anything should happen to the master. Indeed, it has been doubted whether a vessel of the largest class, upon a long voyage, would be seaworthy with no navigator on board but the master. Both the chief and second mates are always addressed by their surnames, with _Mr._ prefixed, and are answered with the addition of _Sir_. This is a requirement of ship's duty, and an intentional omission of it is an offence against the rules and understanding of the service. CHAPTER III. SECOND AND THIRD MATES. SECOND MATE.--Navigation. Station. Watch duties. Day's work. Working ship. Reefing. Furling. Duties aloft. Care of ship's furniture. Stores. Duties in port. THIRD MATE.--Working ship. Day's work. Duties aloft--in port. Boating. Stores. The duties of the second mate are, to command the starboard watch when the master is not on deck, and to lead the crew in their work. It is not necessary that he should be a navigator, or even be able to keep a journal, though he should know enough of navigation to keep the courses and distances during his watch, and to report them correctly on the slate. There are also many advantages in his being acquainted with navigation and able to keep the log, as, in case of the chief mate's meeting with any accident, or being removed from office. The second mate, however, does not, by law, necessarily succeed to the office of chief mate, as the chief mate does to that of master; but it lies with the master for the time being to appoint whom he chooses to the office of chief mate: yet, if the second mate is capable of performing the duties of the office, he would ordinarily be appointed, as a matter of course.