DISPARTING A GUN. To bring the line of sight and line of metal to be parallel by setting up a mark on the muzzle-ring of a cannon, so that a sight-line, taken from the top of the base-ring behind the touch-hole, to the mark set near the muzzle, may be parallel to the axis of the bore. (_See_ GUN.) DISPART-SIGHT. A gun-sight fixed on the top of the second reinforce-ring--about the middle of the piece--for point-blank or horizontal firing, to eliminate the difference of the diameters between the breech and the mouth of the cannon. DISPATCH. All duty is required to be performed with diligence. DISPATCHES. Not simply letters, but such documents as demand every effort for their immediate delivery. "Charged with dispatches" overrides all signals of hindrance on a voyage. DISPLACEMENT. The centre of gravity of the displacement relates to the part of the ship under water, considered as homogeneous. The weight of water which a vessel displaces when floating is the same as the weight of the ship. (_See_ CENTRE OF CAVITY.) DISPOSED QUARTERS. The distribution when the camp is marked about a place besieged. DISPOSITION. A draught representing the several timbers that compose a ship's frame properly disposed with respect to ports and other parts. Also, the arrangement of a ship's company for watches, quarters, reefing, furling, and other duties. In a military sense it means the placing of a body of troops upon the most advantageous ground. DISRANK, OR DISRATE. To degrade in rank or station. DISREPAIR. A bar to any claim on account of sea-unworthiness in a warrantry. DISTANCE. The run which a ship has made upon the log-board. In speaking of double stars, it is the space separating the centres of the two stars, expressed in seconds of arc. (_See_ LUNAR DISTANCES.) DISTILLING SEA-WATER. Apparatus for the conversion of sea-water into potable fresh water have long been invented, though little used; but of late the larger ships are effectively fitted with adaptations for the purpose. DISTINCTION. Flags of distinction, badges, honourable note of superiority. DISTINGUISHING PENDANT. In fleets and squadrons, instead of hoisting several flags to denote the number of the ship on the list of the Navy, pendants are used. Thus ten ships may be signalled separately. If more, then, as one answers, her pendant is hauled down, and then two pendants succeed. (_See_ SIGNALS.) DISTRESS. A term used when a ship requires immediate assistance from unlooked-for damage or danger. (_See_ SIGNAL OF DISTRESS.) DISTRICT ORDERS. Those issued by a general commanding a district. DISTURBANCE. _See_ SPANISH DISTURBANCE.