{Disappearing carriage} (Ordnance), a carriage for heavy
coast guns on which the gun is raised above the parapet
for firing and upon discharge is lowered behind the
parapet for protection. The standard type of disappearing
carriage in the coast artillery of the United States army
is the {Buffington-Crozier carriage}, in which the gun
trunnions are secured at the upper and after ends of a
pair of heavy levers, at the lower ends of which is
attached a counterweight of lead. The levers are pivoted
at their middle points, which are, with the top carriage,
permitted restrained motion along the slightly inclined
chassis rails. The counterweight is held in place by a
pawl and ratchet. When the gun is loaded the pawl is
released and the counterweight sinks, raising the gun to
the firing position above the parapet. The recoil
following the discharge returns the gun to the loading
position, the counterweight rising until the pawl engages
the ratchet.
2. To cease to be or exist; as, the epidemic has disappeared.