This diagram is furnished by an old boatswain.  As a rule, the calls are taught entirely by personal instruction, and it is believed that they have here been put into print for the first time.  None of the ordinary manuals have ever given them, the young sailor having had to learn them by experience on shipboard.

Their importance is evident from the fact that every order aboard ship is preceded by the pipe peculiar to the command; for though the words may not be heard, the whistle can always be distinguished.  Even the most lubberly landsman, with such continuous practice, soon learns the meaning of the different calls, and jumps to obey them.

[Illustration:  THE BOATSWAIN’S CALLS]

[Illustration:  STATIONS OR QUARTERS FOR EXERCISE, OR PRECEDING ACTION, OF FIVE-INCH BREECHLOADING RIFLES.]

1.  First Captain, Second Boarder. 2.  Second Captain, First Boarder. 3.  First Loader, Second Boarder, 4.  Second Loader, First Boarder. 5.  First Shellman, Pumpman, Port guard. 6.  Second Shellman, Fireman, Port guard. 7.  First Shellman, Second Rifleman. 8.  Second Shellman, First Rifleman.

1.  Stands at elevating gear wheel and sights and fires the gun.

2.  Stands at the right and beside the breech; opens same after firing so shell can be taken out.

3.  Stands at the left training wheel—­i.e., the wheel that moves the gun laterally.  He also loads the gun.

4.  Stands at the right training wheel.  He takes out the empty shell after firing, and wears heavy gloves for that purpose.

5 and 6.  Stand just behind No. 2 to the right of the gun.  They may be termed emergency men.  They assist with the shells, carry the wounded, if any; will be called away in case of fire, and are qualified to sight and fire the gun in case the first and second captains are wounded or killed.  They provide revolvers and belts for Nos. 1, 2, and 3, and belts for Nos. 5, 6, 7, and 8.  They are also port guards, and defend the ports in case of close action.

7 and 8.  Carry shells from the ammunition hoist to a position amidships convenient for quick transport to the gun.  They are also riflemen, and may be called to protect any part of the ship from boarders or from fire on shore.